v3.26.3
Label Element Value
Risk/Return: oef_RiskReturnAbstract  
Document Type dei_DocumentType 485BPOS
Document Period End Date dei_DocumentPeriodEndDate May 31, 2026
Registrant Name dei_EntityRegistrantName BNY MELLON CALIFORNIA AMT-FREE MUNICIPAL BOND FUND, INC.
Entity Central Index Key dei_EntityCentralIndexKey 0000720064
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Sep. 25, 2026
Document Effective Date dei_DocumentEffectiveDate Sep. 30, 2026
Entity Investment Company Type dei_EntityInvCompanyType N-1A
Prospectus Date oef_ProspectusDate Sep. 30, 2026
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. | A  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol DCAAX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. | C  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol DCACX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. | I  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol DCMIX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. | Y  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol DCAYX
BNY Mellon California AMT-Free Municipal Bond Fund, Inc. | Z  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol DRCAX