Investor A C Institutional Class R [Member] Investment Strategy - Investor A, C, Institutional and Class R - BLACKROCK CAPITAL APPRECIATION FUND, INC.	May 31, 2025
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	The Fund will seek to achieve its investment objective by investing primarily in a diversified portfolio consisting primarily of common stock of U.S. companies that Fund management believes have exhibited above-average growth rates in earnings over the long term. In other words, Fund management tries to choose investments that will increase in value over the long term. The Fund will generally invest at least 65% of its total assets in the following equity securities: ◼ Common stock; ◼ Convertible preferred stock; and ◼ Rights to subscribe to common stock. Of these securities the Fund generally seeks to invest primarily in common stock. The Fund may also purchase securities convertible into common stock. The Fund may invest in companies of any size but emphasizes investments in companies that have large stock market capitalizations (currently, approximately $2 billion or more). Convertible securities generally are debt securities or preferred stock that may be converted into common stock. Convertible securities typically pay current income as either interest (debt security convertibles) or dividends (preferred stock). A convertible’s value usually reflects both the stream of current income payments and the market value of the underlying common stock. The Fund may purchase securities pursuant to the exercise of subscription rights, which allow an issuer’s existing shareholders to purchase additional common stock at a price substantially below the market price of the shares.

Investor A C Institutional Class R [Member] Investment Strategy - Investor A, C, Institutional and Class R - BLACKROCK CAPITAL APPRECIATION FUND, INC.

May 31, 2025

Principal Investment Strategies of the Fund

Strategy Narrative [Text Block]

The Fund will seek to achieve its investment objective by investing primarily in a diversified portfolio consisting primarily of common stock of U.S. companies that Fund management believes have exhibited above-average growth rates in earnings over the long term. In other words, Fund management tries to choose investments that will increase in value over the long term.

The Fund will generally invest at least 65% of its total assets in the following equity securities:

◼

Common stock;

◼

Convertible preferred stock; and

◼

Rights to subscribe to common stock.

Of these securities the Fund generally seeks to invest primarily in common stock. The Fund may also purchase securities convertible into common stock.

The Fund may invest in companies of any size but emphasizes investments in companies that have large stock market capitalizations (currently, approximately $2 billion or more).

Convertible securities generally are debt securities or preferred stock that may be converted into common stock. Convertible securities typically pay current income as either interest (debt security convertibles) or dividends (preferred stock). A convertible’s value usually reflects both the stream of current income payments and the market value of the underlying common stock. The Fund may purchase securities pursuant to the exercise of subscription rights, which allow an issuer’s existing shareholders to purchase additional common stock at a price substantially below the market price of the shares.