Segments (Reconciliation of Net Income (Loss) to EBITDA) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)
Segment Reporting, Other Significant Reconciling Item [Line Items]
Number of Operating Segments | segment			3
Net income (loss)	$ 39.4	$ (38.1)	$ 61.6	$ (76.4)
Interest and debt expense, net	40.1	35.1	76.2	71.1
Provision for income taxes	0.3	0.1	0.3	0.0
Depreciation, amortization and accretion	80.6	58.8	155.4	118.0
EBITDA	160.4	57.1	293.5	119.4
Loss on modification/extinguishment of debt	0.0	1.2	0.0	6.7
Crestwood Midstream Partners LP
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net income (loss)	(14.6)	(38.5)	5.6	(78.9)
Interest and debt expense, net	40.1	35.1	76.2	71.1
Provision for income taxes	0.2	0.1	0.2	0.0
Depreciation, amortization and accretion	83.0	62.2	161.2	125.0
EBITDA	108.7	60.1	243.2	123.9
Loss on modification/extinguishment of debt	$ 0.0	$ 1.2	$ 0.0	$ 6.7