N-2	Oct. 05, 2026 USD ($)
Cover [Abstract]
Entity Central Index Key	0001280784
Amendment Flag	false
Securities Act File Number	814-00702
Document Type	8-K
Entity Registrant Name	Hercules Capital, Inc.
Entity Address, Address Line One	1 North B Street
Entity Address, Address Line Two	Suite 2000
Entity Address, City or Town	San Mateo
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94401
City Area Code	650
Local Phone Number	289-3060
Entity Emerging Growth Company	false
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Long Term Debt [Table Text Block]	On October 8, 2026, in connection with a previously announced public offering, Hercules Capital, Inc. (the “Company”) and U.S. Bank Trust Company, National Association, as trustee (the “Trustee”), entered into the Twelfth Supplemental Indenture (the “Twelfth Supplemental Indenture”) to that certain indenture, dated March 6, 2012, between the Company and the Trustee (together with the Twelfth Supplemental Indenture, the “Indenture”). The Twelfth Supplemental Indenture relates to the Company’s issuance, offer and sale of $400,000,000 in aggregate principal amount of its 6.700% Notes due 2029 (the “Notes”). The Notes will mature on October 8, 2029, unless previously redeemed or repurchased in accordance with their terms. The interest rate of the Notes is 6.700% per year and will be paid semiannually in arrears on April 8 and October 8 of each year, commencing April 8, 2027. The Notes are the Company’s unsecured obligations that rank senior in right of payment to all of the Company’s existing and future indebtedness that is expressly subordinated, or junior, in right of payment to the Notes. The Notes will not be guaranteed by any of the Company’s current or future subsidiaries. The Notes will rank pari passu, or equally, in right of payment with all of the Company’s existing and future liabilities that are not so subordinated, or junior. The Notes will effectively rank subordinated, or junior, to any of the Company’s secured indebtedness (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness. The Notes will rank structurally subordinated, or junior, to all existing and future indebtedness (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities. The Notes may be redeemed in whole or in part at any time or from time to time at the Company’s option at par, plus a “make whole” premium, if applicable.
Long Term Debt, Principal	$ 400,000,000
Long Term Debt, Structuring [Text Block]	The Notes will mature on October 8, 2029, unless previously redeemed or repurchased in accordance with their terms. The interest rate of the Notes is 6.700% per year and will be paid semiannually in arrears on April 8 and October 8 of each year, commencing April 8, 2027. The Notes are the Company’s unsecured obligations that rank senior in right of payment to all of the Company’s existing and future indebtedness that is expressly subordinated, or junior, in right of payment to the Notes. The Notes will not be guaranteed by any of the Company’s current or future subsidiaries. The Notes will rank pari passu, or equally, in right of payment with all of the Company’s existing and future liabilities that are not so subordinated, or junior. The Notes will effectively rank subordinated, or junior, to any of the Company’s secured indebtedness (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness. The Notes will rank structurally subordinated, or junior, to all existing and future indebtedness (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

0001280784

814-00702

Entity Registrant Name

Hercules Capital, Inc.

Entity Address, Address Line Two

Suite 2000

Entity Address, State or Province

CA

City Area Code

650

Entity Emerging Growth Company

false

Long Term Debt [Table Text Block]

On October 8, 2026, in connection with a previously announced public offering, Hercules Capital, Inc. (the “Company”) and U.S. Bank Trust Company, National Association, as trustee (the “Trustee”), entered into the Twelfth Supplemental Indenture (the “Twelfth Supplemental Indenture”) to that certain indenture, dated March 6, 2012, between the Company and the Trustee (together with the Twelfth Supplemental Indenture, the “Indenture”). The Twelfth Supplemental Indenture relates to the Company’s issuance, offer and sale of $400,000,000 in aggregate principal amount of its 6.700% Notes due 2029 (the “Notes”).

The Notes will mature on October 8, 2029, unless previously redeemed or repurchased in accordance with their terms. The interest rate of the Notes is 6.700% per year and will be paid semiannually in arrears on April 8 and October 8 of each year, commencing April 8, 2027. The Notes are the Company’s unsecured obligations that rank senior in right of payment to all of the Company’s existing and future indebtedness that is expressly subordinated, or junior, in right of payment to the Notes. The Notes will not be guaranteed by any of the Company’s current or future subsidiaries. The Notes will rank pari passu, or equally, in right of payment with all of the Company’s existing and future liabilities that are not so subordinated, or junior. The Notes will effectively rank subordinated, or junior, to any of the Company’s secured indebtedness (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness. The Notes will rank structurally subordinated, or junior, to all existing and future indebtedness (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.

The Notes may be redeemed in whole or in part at any time or from time to time at the Company’s option at par, plus a “make whole” premium, if applicable.

Long Term Debt, Structuring [Text Block]

The Notes will mature on October 8, 2029, unless previously redeemed or repurchased in accordance with their terms. The interest rate of the Notes is 6.700% per year and will be paid semiannually in arrears on April 8 and October 8 of each year, commencing April 8, 2027. The Notes are the Company’s unsecured obligations that rank senior in right of payment to all of the Company’s existing and future indebtedness that is expressly subordinated, or junior, in right of payment to the Notes. The Notes will not be guaranteed by any of the Company’s current or future subsidiaries. The Notes will rank pari passu, or equally, in right of payment with all of the Company’s existing and future liabilities that are not so subordinated, or junior. The Notes will effectively rank subordinated, or junior, to any of the Company’s secured indebtedness (including unsecured indebtedness that the Company later secures) to the extent of the value of the assets securing such indebtedness. The Notes will rank structurally subordinated, or junior, to all existing and future indebtedness (including trade payables) incurred by the Company’s subsidiaries, financing vehicles or similar facilities.