Schedule I - Crestwood Equity Partners LP - Parent Only - Statement of Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ (37.4)	$ (15.3)	$ 319.9
Change in fair value of Suburban Propane Partners, L.P. units	0.0	0.0	0.3
Comprehensive income (loss)	(37.4)	(15.3)	320.2
Parent Company
Condensed Financial Statements, Captions [Line Items]
Change in fair value of Suburban Propane Partners, L.P. units	0.0	0.0	0.3
Comprehensive income (loss)	$ (78.5)	$ (56.1)	$ 285.4