| N-2 - $ / shares | Aug. 18, 2024 | Aug. 16, 2024 | Jun. 30, 2024 | |
| Cover [Abstract] | ||||
| Entity Central Index Key | 0001280784 | |||
| Amendment Flag | false | |||
| Document Type | 424B3 | |||
| Entity Registrant Name | Hercules Capital, Inc. | |||
| General Description of Registrant [Abstract] | ||||
| Investment Objectives and Practices [Text Block] | Our investment objective is to maximize our portfolio total return by generating current income from our debt investments and capital appreciation from our warrant and equity-related investments. | |||
| Risk Factors [Table Text Block] | RISK FACTORS The following disclosure supersedes and replaces the first paragraph of the risk factor titled “Stockholders may incur dilution if we sell shares of our common stock in one or more offerings at prices below the then-current NAV per share of our common stock or issue securities to subscribe to, convert to or purchase shares of our common stock.” on page S-3 The 1940 Act prohibits us from selling shares of our common stock at a price below the current NAV per share of such stock, with certain exceptions. One such exception is prior stockholder approval of issuances below NAV provided that our Board makes certain determinations. On August 15, 2024, we obtained authorization from our stockholders to issue common stock at a price below our then-current NAV per share for a twelve-month period expiring on August 15, 2025. We may seek to obtain this authorization again in the future. Our stockholders have previously approved a proposal to authorize us to issue securities to subscribe to, convert to, or purchase shares of our common stock in one or more offerings. Even though we have obtained authorization from our stockholders to issue common stock at a price below our then-current NAV, we cannot predict whether we will make any Below-NAV | |||
| Share Price [Table Text Block] | The following disclosure supersedes and replaces the table on page S-12 Example 1 Example 2 Shares Of Our Common Stock Offered 25,000,000 25,000,000 Purchase Price $ 10.00 $ 9.00 Discount to NAV(1) 12.5 % 21.3 % (1) Assumes NAV per share of $11.43, which was our NAV as of June 30, 2024 (the most recent date NAV was determined). | |||
| NAV Per Share | $ 11.43 | |||
| RISK FACTORS [Member] | ||||
| General Description of Registrant [Abstract] | ||||
| Risk [Text Block] | RISK FACTORS The following disclosure supersedes and replaces the first paragraph of the risk factor titled “Stockholders may incur dilution if we sell shares of our common stock in one or more offerings at prices below the then-current NAV per share of our common stock or issue securities to subscribe to, convert to or purchase shares of our common stock.” on page S-3 The 1940 Act prohibits us from selling shares of our common stock at a price below the current NAV per share of such stock, with certain exceptions. One such exception is prior stockholder approval of issuances below NAV provided that our Board makes certain determinations. On August 15, 2024, we obtained authorization from our stockholders to issue common stock at a price below our then-current NAV per share for a twelve-month period expiring on August 15, 2025. We may seek to obtain this authorization again in the future. Our stockholders have previously approved a proposal to authorize us to issue securities to subscribe to, convert to, or purchase shares of our common stock in one or more offerings. Even though we have obtained authorization from our stockholders to issue common stock at a price below our then-current NAV, we cannot predict whether we will make any Below-NAV | |||
| Example 1 [Member] | ||||
| General Description of Registrant [Abstract] | ||||
| Share Price | $ 10 | |||
| Latest Premium (Discount) to NAV [Percent] | [1] | 12.50% | ||
| Example 2 [Member] | ||||
| General Description of Registrant [Abstract] | ||||
| Share Price | $ 9 | |||
| Latest Premium (Discount) to NAV [Percent] | [1] | 21.30% | ||
| [1]Assumes NAV per share of $11.43, which was our NAV as of June 30, 2024 (the most recent date NAV was determined). | ||||
