Schedule I - Crestwood Equity Partners LP - Parent Only - Statement of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 2,632.8	$ 3,931.3	$ 1,426.7
Operating income (loss)	(2,084.8)	117.9	28.2
Interest and debt expense, net	(140.1)	(127.1)	(77.9)
Loss on modification/extinguishment of debt	(20.0)	0.0	0.0
Other income, net	0.6	0.6	0.2
Loss before income taxes	(2,305.1)	(9.3)	(49.6)
Provision (benefit) for income taxes	(1.4)	1.1	1.0
Net loss	(2,303.7)	(10.4)	(50.6)
Net income attributable to non-controlling partners in subsidiary	636.8	66.8	57.3
Net income (loss) attributable to parent	(1,666.9)	56.4	6.7
Parent Company
Condensed Financial Statements, Captions [Line Items]
Revenues	0.0	0.0	0.0
Costs and Expenses	14.5	8.5	0.0
Operating income (loss)	(14.5)	(8.5)	0.0
Interest and debt expense, net	(9.6)	(15.7)	(6.5)
Loss from unconsolidated affiliates	(2,279.1)	14.2	(43.9)
Loss on modification/extinguishment of debt	(1.1)	0.0	0.0
Other income, net	0.6	0.0	0.0
Loss before income taxes	(2,303.7)	(10.0)	(50.4)
Provision (benefit) for income taxes	0.0	0.4	0.2
Net loss	(2,303.7)	(10.4)	(50.6)
Net income attributable to non-controlling partners in subsidiary	(6.2)	0.0	0.0
Net income (loss) attributable to parent	$ (2,309.9)	$ (10.4)	$ (50.6)