Class K [Member] Expense Example - Class K [Member] - BLACKROCK CAPITAL APPRECIATION FUND, INC. - Class K	May 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 63
Expense Example, with Redemption, 3 Years	205
Expense Example, with Redemption, 5 Years	359
Expense Example, with Redemption, 10 Years	$ 808

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Form N-1A
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
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