Annual report pursuant to Section 13 and 15(d)

Debt - Additional Information (Details)

v3.22.4
Debt - Additional Information (Details)
12 Months Ended
Jan. 13, 2023
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Jan. 13, 2023
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Feb. 22, 2022
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Jan. 20, 2022
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Sep. 16, 2021
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Mar. 04, 2021
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Oct. 27, 2020
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Dec. 31, 2022
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Firm
Dec. 31, 2021
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Firm
Dec. 31, 2020
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Jun. 23, 2022
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Jun. 22, 2022
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Feb. 01, 2022
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shares
Nov. 04, 2020
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Jun. 03, 2020
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Feb. 05, 2020
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Jul. 16, 2019
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Sep. 24, 2018
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Oct. 23, 2017
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Jan. 25, 2017
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Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 2,185,000,000 $ 1,745,000,000                      
Repayment of debt               931,198,000 1,787,043,000 $ 827,405,000                    
Debt issuance costs               22,642,000 16,035,000                      
Restricted cash (amounts related to a VIE $8,346 and $0, respectively)               $ 10,079,000 3,150,000 39,340,000                    
Line of credit facility, termination date               Nov. 09, 2026                        
Investments at Fair Value               $ 2,963,955,000 2,434,522,000                      
Loss on extinguishment of debt               $ (3,686,000) (4,419,000) $ 0                    
Line of Credit Facility, Description               Availability under the SMBC Facility will terminate on November 7, 2025, and the outstanding loans under the SMBC Facility will mature on November 9, 2026.                        
Secured Credit Facility with M U F G Bank Ltd. (M U F G) [Member] | Subsequent Event [Member]                                        
Debt Instrument [Line Items]                                        
Line of Credit Facility, Covenant Terms   (vi) modify the minimum tangible net worth covenant to an amount that is in excess of $869.0 million.                                    
Line of credit facility, termination date Jan. 13, 2026                                      
Interest rate plus applicable margin adjustment 2.75%                                      
Secured Credit Facility with M U F G Bank Ltd. (M U F G) [Member] | Minimum | Subsequent Event [Member]                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity $ 400,000,000.0 $ 400,000,000.0                                    
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage 0.75%                                      
Secured Credit Facility with M U F G Bank Ltd. (M U F G) [Member] | Maximum                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity $ 545,000,000.0 545,000,000.0           $ 545,000,000.0                        
Secured Credit Facility with M U F G Bank Ltd. (M U F G) [Member] | Maximum | Subsequent Event [Member]                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity $ 600,000,000.0 600,000,000.0                                    
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage 0.375%                                      
MUFG Bank Facility                                        
Debt Instrument [Line Items]                                        
Line of credit facility, termination date               Feb. 22, 2024                        
Line of Credit Facility, Description               The MUFG Bank Facility contains an accordion feature, in which the Company can increase the credit line up to an aggregate of $600.0 million, funded by existing or additional lenders and with the agreement of MUFG Bank and subject to other customary conditions.                        
MUFG Bank Facility | Lender [Member]                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity                 400,000.0                      
MUFG Bank Facility | Minimum                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity               $ 545,000,000.0                        
MUFG Bank Facility | Maximum                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity $ 600,000,000.0 $ 600,000,000.0                                    
MUFG Bank Facility | One-month interest period                                        
Debt Instrument [Line Items]                                        
Interest rate plus applicable margin adjustment               2.60%                        
MUFG Bank Facility | Three-month interest period                                        
Debt Instrument [Line Items]                                        
Interest rate plus applicable margin adjustment               2.65%                        
SMBC Facility                                        
Debt Instrument [Line Items]                                        
Line of credit facility, termination date               Nov. 07, 2025                        
Maximum borrowing capacity               $ 225,000,000.0                        
Line of Credit Facility, Description               the SMBC Facility provides for the issuance of letters of credit on the account of the Company or its designee in U.S. dollars and certain agreed upon foreign currencies in an aggregate face amount not to exceed $15.0 million.                        
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage               0.375%                        
SMBC Facility | Subsequent Event [Member]                                        
Debt Instrument [Line Items]                                        
Commitment amount $ 100,000,000.0                                      
SMBC Facility | Minimum                                        
Debt Instrument [Line Items]                                        
Interest rate plus applicable margin adjustment               0.875%                        
SMBC Facility | Maximum                                        
Debt Instrument [Line Items]                                        
Interest rate plus applicable margin adjustment               2.00%                        
Revolving Credit Facility [Member]                                        
Debt Instrument [Line Items]                                        
Debt average amount outstanding               $ 127,700,000 $ 28,800,000                      
Line of credit interest rate               4.51% 2.54%                      
SBA Debentures                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount [1]               $ 175,000,000 $ 175,000,000                      
Debt issuance costs               5,262,000 5,002,000                      
2022 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 0 150,000,000                   $ 150,000,000.0  
Debt instrument, interest rate               4.625%                        
Debt Instrument Maturity Date               Oct. 23, 2022                        
Debt issuance costs               $ 0 300,000                      
Debt Instrument, redemption, description               On October 23, 2017, the Company issued $150.0 million in aggregate principal amount of 4.625% interest-bearing unsecured notes that mature on October 23, 2022 (the “2022 Notes”), unless repurchased in accordance with their terms.                        
Repayment of debt     $ 150,000,000.0                                  
Interest payable     2,300,000                                  
2022 Notes | Prepayment Fees [Member]                                        
Debt Instrument [Line Items]                                        
Loss on extinguishment of debt     3,300,000                                  
2022 Notes | Debt Issuance Cost [Member]                                        
Debt Instrument [Line Items]                                        
Loss on extinguishment of debt     $ 300,000                                  
2022 Convertible Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 0 230,000,000                     $ 230,000,000.0
Debt instrument, interest rate               4.375%                        
Debt Instrument Maturity Date               Feb. 01, 2022                        
Debt issuance costs               $ 0 149,000                      
Debt Instrument, redemption, description               On January 25, 2017, the Company issued $230.0 million in aggregate principal amount of 4.375% interest-bearing unsecured notes due on February 1, 2022 (the “2022 Convertible Notes”), unless previously converted or caused to repurchase the notes in accordance with their terms by the holders of the 2022 Convertible Notes.                        
Repayment of debt                         $ 230,000,000.0              
Interest payable                         $ 5,000,000.0              
Convertible Debt Redemption Shares Issued on Redemption | shares                         981,169              
2022 Convertible Notes | Additional Face Amount [Member]                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount                                       $ 30,000,000.0
July 2024 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 105,000,000 105,000,000               $ 105,000,000.0      
Debt instrument, interest rate               4.77%                        
Debt Instrument Maturity Date               Jul. 16, 2024                        
Debt issuance costs               $ 467,000 762,000                      
Debt instrument, payment terms, description               Interest on the July 2024 Notes is due semiannually.                        
Debt Instrument, redemption, description               On July 16, 2019, the Company issued $105.0 million in aggregate principal amount of 4.77% interest-bearing unsecured notes due on July 16, 2024 (the “July 2024 Notes”), unless repurchased in accordance with their terms, to qualified institutional investors in a private placement notes offering.                        
Debt Instrument, Collateral               The July 2024 Notes are general unsecured obligations of the Company that rank pari passu with all outstanding and future unsecured unsubordinated indebtedness issued by the Company.                        
February 2025 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 50,000,000 50,000,000             $ 50,000,000.0        
Debt instrument, interest rate               4.28%                        
Debt Instrument Maturity Date               Feb. 05, 2025                        
Debt issuance costs               $ 249,000 363,000                      
Debt instrument, payment terms, description               Interest on the February 2025 Notes is due semiannually.                        
Debt Instrument, redemption, description               On February 5, 2020, the Company issued $50.0 million in aggregate principal amount of 4.28% interest-bearing unsecured notes due February 5, 2025 (the “February 2025 Notes”), unless repurchased in accordance with their terms, to qualified institutional investors in a private placement notes offering.                        
Debt Instrument, Collateral               The February 2025 Notes are general unsecured obligations of the Company that rank pari passu with all outstanding and future unsecured unsubordinated indebtedness issued by the Company.                        
June 2025 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 70,000,000 70,000,000           $ 70,000,000.0          
Debt instrument, interest rate               4.31%                        
Debt Instrument Maturity Date               Jun. 03, 2025                        
Debt issuance costs               $ 405,000 567,000                      
Debt instrument, payment terms, description               Interest on the June 2025 Notes is due semiannually.                        
Debt Instrument, redemption, description               On June 3, 2020, the Company issued $70.0 million in aggregate principal amount of 4.31% interest-bearing unsecured notes due June 3, 2025 (the “June 2025 Notes”), unless repurchased in accordance with their terms, to qualified institutional investors in a private placement notes offering pursuant to the June 2025 Notes indenture.                        
Debt Instrument, Collateral               The June 2025 Notes are general unsecured obligations of the Company that rank pari passu with all outstanding and future unsecured unsubordinated indebtedness issued by the Company.                        
June 2025 3-Year Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 50,000,000 0   $ 50,000,000.0                  
Debt instrument, interest rate               6.00%                        
Debt Instrument Maturity Date               Jun. 23, 2025                        
Debt issuance costs               $ 384,000 0                      
Debt instrument, payment terms, description               Interest on the June 2025 3-Year Notes is due semiannually.                        
Debt Instrument, redemption, description               On June 23, 2022, the Company issued $50.0 million in aggregate principal amount of 6.00% interest-bearing unsecured notes due June 23, 2025 (the “June 2025 3-Year Notes”), unless repurchased in accordance with their terms, to qualified institutional investors in a private placement notes offering.                        
Debt Instrument, Collateral               The June 2025 3-Year Notes are general unsecured obligations of the Company that rank pari passu with all outstanding and future unsecured unsubordinated indebtedness issued by the Company.                        
March 2026 A Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 50,000,000 50,000,000         $ 50,000,000.0            
Debt instrument, interest rate               4.50%                        
Debt Instrument Maturity Date               Mar. 04, 2026                        
Debt issuance costs               $ 300,000 395,000                      
Debt instrument, payment terms, description               Interest on the March 2026 A Notes is due semiannually.                        
Debt Instrument, redemption, description               On November 4, 2020, the Company issued $50.0 million in aggregate principal amount of 4.5% interest-bearing unsecured notes due March 4, 2026 (the “March 2026 A Notes”), unless repurchased in accordance with their terms, to qualified institutional investors in a private placement notes offering.                        
Debt Instrument, Collateral               The March 2026 A Notes are general unsecured obligations of the Company that rank pari passu with all outstanding and future unsecured unsubordinated                        
March 2026 B Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount           $ 50,000,000.0   $ 50,000,000 50,000,000                      
Debt instrument, interest rate               4.55%                        
Debt Instrument Maturity Date               Mar. 04, 2026                        
Debt issuance costs               $ 327,000 430,000                      
Debt instrument, payment terms, description               Interest on the March 2026 B Notes is due semiannually.                        
Net proceeds from sale of Notes           49,500,000                            
Debt Instrument, redemption, description               On March 4, 2021, the Company issued $50.0 million in aggregate principal amount of 4.55% interest-bearing unsecured notes due March 4, 2026 (the “March 2026 B Notes”), unless repurchased in accordance with their terms, to qualified institutional investors in a private placement pursuant note offering.                        
Debt Instrument, Collateral               The March 2026 B Notes are general unsecured obligations of the Company that rank pari passu with all outstanding and future unsecured unsubordinated indebtedness issued by the Company.                        
Aggregate Debt Issuance Cost           $ 500,000                            
September 2026 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount         $ 325,000,000.0     $ 325,000,000 325,000,000                      
Debt instrument, interest rate               2.625%                        
Debt Instrument Maturity Date               Sep. 16, 2026                        
Debt issuance costs               $ 3,642,000 4,624,000                      
Debt instrument, payment terms, description               Interest on the September 2026 Notes is payable semi-annually in arrears on March 16 and September 16 of each year, commencing on March 16, 2022.                        
Net proceeds from sale of Notes         320,100,000                              
Debt Instrument, Collateral               The September 2026 Notes are general unsecured obligations and rank pari passu, or equally in right of payment, with all outstanding and future unsecured unsubordinated indebtedness issued by the Company. The Company may redeem some or all of the September 2026 Notes at any time, or from time to time, at the redemption price set forth under the terms of the September 2026 Notes Indenture.                        
Aggregate Debt Issuance Cost         4,100,000                              
Aggregate Discount On Issuance         $ 800,000                              
January 2027 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount       $ 350,000,000.0       $ 350,000,000 0                      
Debt instrument, interest rate               3.375%                        
Debt Instrument Maturity Date               Jan. 20, 2027                        
Debt issuance costs               $ 5,396,000 0                      
Debt instrument, payment terms, description               Interest on the January 2027 Notes is payable semi-annually in arrears on January 20 and July 20 of each year, commencing on July 20, 2022.                        
Net proceeds from sale of Notes       343,400,000                                
Debt Instrument, redemption, description               The Company may redeem some or all of the January 2027 Notes at any time, or from time to time, at the redemption price set forth under the terms of the January 2027 Notes Indenture.                        
Debt Instrument, Collateral               The January 2027 Notes are general unsecured obligations and rank pari passu, or equally in right of payment, with all outstanding and future unsecured unsubordinated indebtedness issued by the Company.                        
Aggregate Debt Issuance Cost       4,100,000                                
Aggregate Discount On Issuance       $ 2,500,000                                
2031 Asset-Backed Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 150,000,000 0     $ 150,000,000.0                
Debt instrument, interest rate               4.95%                        
Debt Instrument Maturity Date               Jul. 20, 2031                        
Debt issuance costs               $ 2,043,000 0                      
Debt instrument, payment terms, description               Interest on the 2031 Asset-Backed Notes will be paid, to the extent of funds available.                        
Restricted cash (amounts related to a VIE $8,346 and $0, respectively)               $ 10,100,000 0                      
2033 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount               $ 40,000,000 40,000,000                 $ 40,000,000.0    
Debt instrument, interest rate               6.25%                        
Debt Instrument Maturity Date               Oct. 30, 2033                        
Debt issuance costs               $ 1,174,000 1,282,000                      
Debt instrument, payment terms, description               Interest on the 2033 Notes is payable quarterly in arrears on January 30, April 30, July 30, and October 30 of each year.                        
Debt Instrument, redemption, description               The Company may redeem some or all of the 2033 Notes at any time, or from time to time, at the redemption price set forth under the terms of the 2033 Notes indenture after October 30, 2023.                        
SMBC Facility                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount [2]               $ 225,000,000 100,000,000                      
Debt issuance costs [3]               1,701,000 922,000                      
Maximum borrowing capacity                 $ 100,000,000.0                      
Foreign Currency Borrowing Member | SMBC Facility | Maximum                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity               15,000,000.0                        
HC IV                                        
Debt Instrument [Line Items]                                        
License term             10 years                          
Regulatory capital commitment amount             $ 87,500,000                          
Debt Instrument Face Amount               $ 175,000,000.0                        
Investments held by number of companies | Firm               21 15                      
Percentage of total investment portfolio               11.60% 10.00%                      
Percentage of total assets held               11.50% 9.50%                      
Maximum borrowing capacity             $ 175,000,000.0                          
Debt Instrument License Description               HC IV received its license to operate as a SBIC on October 27, 2020. The license has a 10-year term.                        
Investments at Fair Value               $ 343,700,000 $ 244,500,000                      
Tangible assets               $ 348,600,000 $ 245,700,000                      
[1] Availability subject to the Company meeting the borrowing base requirements.
[2] The June 2022 amendment of the MUFG Bank Facility replaced the Union Bank Facility via an amendment which changed the lead lender.
[3] The MUFG Bank Facility (f.k.a. Union Bank Facility) and SMBC Facility, are line-of-credit arrangements, the debt issuance costs associated with these
instruments are included within Other assets on the Consolidated Statements of Assets and Liabilities in accordance with ASC Subtopic 835-30