Document and Entity Information	Total
Prospectus:
Document Type	497
Document Period End Date	Jan. 31, 2020
Entity Registrant Name	GENERAL NEW YORK AMT-FREE MUNICIPAL MONEY MARKET FUND
Entity Central Index Key	0000803950
Entity Inv Company Type	N-1A
Amendment Flag	false
Document Creation Date	Nov. 18, 2020
Document Effective Date	Feb. 01, 2021
Prospectus Date	Nov. 18, 2020
Class A Prospectus \| General Money Market Fund, Inc. \| Class A \| GENERAL MONEY MARKET FUND, INC.
Prospectus:
Trading Symbol	GMMXX
Class A Prospectus \| General Municipal Money Market Fund \| General Municipal Money Market Fund - Class A \| GENERAL MUNICIPAL MONEY MARKET FUNDS, INC.
Prospectus:
Trading Symbol	GTMXX
Class A Prospectus \| General New York AMT-Free Municipal Money Market Fund \| Class A \| GENERAL NEW YORK AMT-FREE MUNICIPAL MONEY MARKET FUND
Prospectus:
Trading Symbol	GNMXX
Class B Prospectus \| General Money Market Fund, Inc. \| Class B \| GENERAL MONEY MARKET FUND, INC.
Prospectus:
Trading Symbol	GMBXX
Class B Prospectus \| General Municipal Money Market Fund \| General Municipal Money Market Fund - Class B \| GENERAL MUNICIPAL MONEY MARKET FUNDS, INC.
Prospectus:
Trading Symbol	GBMXX
Class B Prospectus \| General New York AMT-Free Municipal Money Market Fund \| Class B \| GENERAL NEW YORK AMT-FREE MUNICIPAL MONEY MARKET FUND
Prospectus:
Trading Symbol	GNYXX
Dreyfus Class Prospectus \| General Money Market Fund, Inc. \| Dreyfus Class \| GENERAL MONEY MARKET FUND, INC.
Prospectus:
Trading Symbol	GMGXX

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