Label	Element	Value
Dreyfus Government Securities Cash Management
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	ck0000740766_SupplementTextBlock	August 24, 2016 Dreyfus GOVERNMENT Cash Management FUNDS -Dreyfus Government Securities Cash Management Supplement to Current Prospectus
Risk/Return [Heading]	rr_RiskReturnHeading	Dreyfus Government Securities Cash Management
Strategy [Heading]	rr_StrategyHeading	The following information supersedes and replaces "Fund Summary – Dreyfus Government Securities Cash Management – Principal Investment Strategy":
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The fund pursues its investment objective by investing only in government securities (i.e., securities issued or guaranteed as to principal and interest by the U.S. government or its agencies or instrumentalities, including those with floating or variable rates of interest) and cash. The fund is a money market fund subject to the maturity, quality, liquidity and diversification requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended ("Rule 2a-7"), and seeks to maintain a stable share price of $1.00. The fund is a "government money market fund," as that term is defined in Rule 2a-7, and as such is required to invest at least 99.5% of its total assets in securities issued or guaranteed as to principal and interest by the U.S. government or its agencies or instrumentalities, repurchase agreements collateralized solely by cash and/or government securities, and cash. The fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in government securities (i.e., under normal circumstances, the fund will not invest more than 20% of its net assets in cash), and typically invests exclusively in government securities. The securities in which the fund invests include those backed by the full faith and credit of the U.S. government, which include U.S. Treasury securities as well as securities issued by certain agencies of the U.S. government, and those that are neither insured nor guaranteed by the U.S. government. While the fund is permitted to invest in the full range of government securities, the fund currently is managed so that income paid by the fund will be exempt from state and local taxes. Because rules regarding the state and local taxation of dividend income can differ from state to state, investors are urged to consult their tax advisers about the taxation of the fund's dividend income in their state and locality.

Label

Element

Value

Dreyfus Government Securities Cash Management

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

ck0000740766_SupplementTextBlock

August 24, 2016

Dreyfus GOVERNMENT Cash Management FUNDS
-Dreyfus Government Securities Cash Management

Supplement to Current Prospectus

Risk/Return [Heading]

rr_RiskReturnHeading

Dreyfus Government Securities Cash Management

Strategy [Heading]

rr_StrategyHeading

The following information supersedes and replaces "Fund Summary – Dreyfus Government Securities Cash Management – Principal Investment Strategy":

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund pursues its investment objective by investing only in government securities (i.e., securities issued or guaranteed as to principal and interest by the U.S. government or its agencies or instrumentalities, including those with floating or variable rates of interest) and cash. The fund is a money market fund subject to the maturity, quality, liquidity and diversification requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended ("Rule 2a-7"), and seeks to maintain a stable share price of $1.00.

The fund is a "government money market fund," as that term is defined in Rule 2a-7, and as such is required to invest at least 99.5% of its total assets in securities issued or guaranteed as to principal and interest by the U.S. government or its agencies or instrumentalities, repurchase agreements collateralized solely by cash and/or government securities, and cash. The fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in government securities (i.e., under normal circumstances, the fund will not invest more than 20% of its net assets in cash), and typically invests exclusively in government securities.

The securities in which the fund invests include those backed by the full faith and credit of the U.S. government, which include U.S. Treasury securities as well as securities issued by certain agencies of the U.S. government, and those that are neither insured nor guaranteed by the U.S. government. While the fund is permitted to invest in the full range of government securities, the fund currently is managed so that income paid by the fund will be exempt from state and local taxes. Because rules regarding the state and local taxation of dividend income can differ from state to state, investors are urged to consult their tax advisers about the taxation of the fund's dividend income in their state and locality.