Quarterly report pursuant to Section 13 or 15(d)

Debt - Additional Information (Details)

v3.22.2.2
Debt - Additional Information (Details)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Jun. 23, 2022
USD ($)
Feb. 22, 2022
USD ($)
Jan. 20, 2022
USD ($)
Sep. 16, 2021
USD ($)
Mar. 04, 2021
USD ($)
Oct. 27, 2020
USD ($)
Sep. 30, 2022
USD ($)
Sep. 30, 2021
USD ($)
Sep. 30, 2022
USD ($)
Firm
Sep. 30, 2021
USD ($)
Dec. 31, 2021
USD ($)
Jun. 22, 2022
USD ($)
Feb. 01, 2022
USD ($)
shares
Nov. 04, 2020
USD ($)
Jun. 03, 2020
USD ($)
Feb. 05, 2020
USD ($)
Jul. 16, 2019
USD ($)
Sep. 24, 2018
USD ($)
Oct. 23, 2017
USD ($)
Jan. 25, 2017
USD ($)
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount             $ 2,185,000   $ 2,185,000   $ 1,745,000               $ 150,000  
Investment Owned At Fair Value             $ 2,825,738   $ 2,825,738   2,434,522                  
Debt instrument, interest rate             4.625%   4.625%                      
Debt Instrument Maturity Date                 Oct. 23, 2022                      
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                                    
Interest payable   2,300                                    
Gain (loss) on extinguishment of debt             $ 0 $ (1,702) $ (3,686) $ (1,702)                    
Restricted cash (amounts related to a VIE $8,346 and $0, respectively)             8,346 $ 13,509 $ 8,346 $ 13,509 3,150                  
Line of credit facility, termination date                 Nov. 09, 2026                      
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.                      
Variable Interest Entity Primary Beneficiary [Member]                                        
Debt Instrument [Line Items]                                        
Restricted cash (amounts related to a VIE $8,346 and $0, respectively)             8,346   $ 8,346   0                  
MUFG Bank Facility                                        
Debt Instrument [Line Items]                                        
Line of Credit Facility, Covenant Terms                 these covenants require the Company to maintain certain financial ratios, including a minimum interest coverage ratio with respect to Hercules Funding IV and a minimum tangible net worth in an amount that is in excess of $723.0 million.                      
Line of credit facility, termination date                 Feb. 22, 2024                      
Minimum tangible net worth amount             723,000   $ 723,000                      
Maximum borrowing capacity             545,000   $ 545,000                      
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 | Maximum                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity             600,000   $ 600,000                      
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%                      
MUFG Bank Facility | Lender [Member]                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity                     400,000                  
S M B C Facility [Member]                                        
Debt Instrument [Line Items]                                        
Line of credit facility, termination date                 Nov. 07, 2025                      
Maximum borrowing capacity             225,000   $ 225,000   100,000                  
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%                      
S M B C Facility [Member] | Minimum                                        
Debt Instrument [Line Items]                                        
Interest rate plus applicable margin adjustment                 0.875%                      
S M B C Facility [Member] | Maximum                                        
Debt Instrument [Line Items]                                        
Interest rate plus applicable margin adjustment                 2.00%                      
Credit Facility [Member]                                        
Debt Instrument [Line Items]                                        
Debt average amount outstanding                 $ 115,600   $ 28,800                  
Line of credit interest rate                 3.70%   2.54%                  
Debt Issuance Cost                                        
Debt Instrument [Line Items]                                        
Gain (loss) on extinguishment of debt   (300)                                    
Prepayment Fees                                        
Debt Instrument [Line Items]                                        
Gain (loss) on extinguishment of debt   $ (3,300)                                    
Foreign Currency Borrowing Member | S M B C Facility [Member] | Maximum                                        
Debt Instrument [Line Items]                                        
Maximum borrowing capacity             15,000   $ 15,000                      
2022 Convertible Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount             $ 0   $ 0   $ 230,000                 $ 230,000
Debt instrument, interest rate             4.375%   4.375%                      
Debt Instrument Maturity Date                 Feb. 01, 2022                      
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              
Interest payable                         $ 5,000              
Debt instrument, payment terms, description                 Interest on the 2022 Convertible Notes is due semiannually in arrears on February 1 and August 1 of each year                      
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
July 2024 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount                                 $ 105,000      
Debt instrument, interest rate             4.77%   4.77%                      
Debt Instrument Maturity Date                 Jul. 16, 2024                      
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, payment terms, description                 Interest on the July 2024 Notes is due semiannually                      
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        
Debt instrument, interest rate             4.28%   4.28%                      
Debt Instrument Maturity Date                 Feb. 05, 2025                      
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, payment terms, description                 Interest on the February 2025 Notes is due semiannually                      
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          
Debt instrument, interest rate             4.31%   4.31%                      
Debt Instrument Maturity Date                 Jun. 03, 2025                      
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.                      
Debt instrument, payment terms, description                 Interest on the June 2025 Notes is due semiannually.                      
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                                      
Debt instrument, interest rate             6.00%   6.00%                      
Debt Instrument Maturity Date Jun. 23, 2025                                      
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, payment terms, description                 Interest on the June 2025 3-Year Notes is due semiannually.                      
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            
Debt instrument, interest rate             4.50%   4.50%                      
Debt Instrument Maturity Date                 Mar. 04, 2026                      
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, payment terms, description                 Interest on the March 2026 A Notes is due semiannually                      
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 indebtedness issued by the Company.                      
March 2026 B Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount         $ 50,000                              
Debt instrument, interest rate             4.55%   4.55%                      
Debt Instrument Maturity Date                 Mar. 04, 2026                      
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, payment terms, description                 Interest on the March 2026 B Notes is due semiannually                      
Net proceeds from sale of Notes         49,500                              
Aggregate Debt Issuance Cost         $ 500                              
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.                      
September 2026 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount       $ 325,000                                
Debt instrument, interest rate             2.625%   2.625%                      
Debt Instrument Maturity Date                 Sep. 16, 2026                      
Debt Instrument, redemption, description                 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.                      
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                                
Aggregate Debt Issuance Cost       4,100                                
Aggregate Discount On Issuance       $ 800                                
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.                      
January 2027 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount     $ 350,000                                  
Debt instrument, interest rate             3.375%   3.375%                      
Debt Instrument Maturity Date                 Jan. 20, 2027                      
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, 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                                  
Aggregate Debt Issuance Cost     4,100                                  
Aggregate Discount On Issuance     $ 2,500                                  
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.                      
2031 Asset-Backed Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount                       $ 150,000                
Debt instrument, interest rate             4.95%   4.95%                      
Debt Instrument Maturity Date                 Jul. 20, 2031                      
Debt instrument, payment terms, description                 Interest on the 2031 Asset-Backed Notes will be paid, to the extent of funds available.                      
2031 Asset-Backed Notes | Variable Interest Entity Primary Beneficiary [Member]                                        
Debt Instrument [Line Items]                                        
Restricted cash (amounts related to a VIE $8,346 and $0, respectively)             $ 8,300   $ 8,300   $ 0                  
2033 Notes                                        
Debt Instrument [Line Items]                                        
Debt Instrument Face Amount                                   $ 40,000    
Debt instrument, interest rate             6.25%   6.25%                      
Debt Instrument Maturity Date                 Oct. 30, 2033                      
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.                      
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, Collateral                 The 2033 Notes trade on the NYSE under the symbol “HCXY.” The 2033 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.                      
HC IV                                        
Debt Instrument [Line Items]                                        
License term           10 years                            
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.                      
Regulatory capital commitment amount           $ 87,500                            
Debt Instrument Face Amount             $ 175,000   $ 175,000                      
Investments held by number of companies | Firm                 18                      
Investment Owned At Fair Value             $ 277,100   $ 277,100                      
Percentage of total investment portfolio             9.80%   9.80%                      
Tangible Assets             $ 287,600   $ 287,600                      
Percentage of total assets held             9.80%   9.80%                      
Maximum borrowing capacity           $ 175,000                            
HC IV | SBA Commitment Fee [Member]                                        
Debt Instrument [Line Items]                                        
Debt issuance cost             $ 1,750   $ 1,750                      
HC IV | SBA Facility Fee [Member]                                        
Debt Instrument [Line Items]                                        
Debt issuance cost             $ 4,200   $ 4,200