Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 319.9	$ 67.0	$ (166.6)
Change in fair value of Suburban Propane Partners, L.P. units	0.3	(0.7)	(0.8)
Comprehensive income (loss)	320.2	66.3	(167.4)
Comprehensive income (loss) attributable to non-controlling partners	34.8	16.2	25.3
Comprehensive income (loss) attributable to Crestwood Equity Partners LP	$ 285.4	$ 50.1	$ (192.7)