Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 4.6	$ 33.6	$ (43.1)	$ 272.7
Change in fair value of Suburban Propane Partners, L.P. units	0.3	(0.1)	(0.8)	0.6
Comprehensive income (loss)	4.9	33.5	(43.9)	273.3
Comprehensive income attributable to non-controlling partner	10.3	9.9	30.4	24.5
Comprehensive income (loss) attributable to Crestwood Equity Partners LP	$ (5.4)	$ 23.6	$ (74.3)	$ 248.8