Organization and Business Description (Details) shares in Millions, $ in Millions	1 Months Ended	9 Months Ended
	Mar. 31, 2021 USD ($) shares	Sep. 30, 2021 segment
Partnership Organization And Basis Of Presentation [Line Items]
Number of Operating Segments | segment		3
Cash Paid to Repurchase Common Stock | $	$ 268
Common Units
Partnership Organization And Basis Of Presentation [Line Items]
Stock exchanged (in shares)	11.5
Subordinated Units
Partnership Organization And Basis Of Presentation [Line Items]
Stock exchanged (in shares)	0.4
Crestwood Midstream Partners LP | Crestwood Gas Services GP, LLC
Partnership Organization And Basis Of Presentation [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		0.10%
Crestwood Midstream Partners LP | Crestwood Equity Partners LP
Partnership Organization And Basis Of Presentation [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		99.90%
Crestwood Holdings LP | Crestwood Equity Partners LP
Partnership Organization And Basis Of Presentation [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest	99.00%
Crestwood Holdings LP | Crestwood Gas Services Holdings LLC
Partnership Organization And Basis Of Presentation [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		1.00%