Certain Balance Sheet Information (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Accrued Expenses and Other Liabilities [Line Items]
Operating leases	$ 10.4	$ 13.2
Finance leases	30.5	1.7
Contract liabilities	11.0	10.7
Total CMLP accrued expenses and other liabilities	190.3	147.1
Contract liabilities	202.1	187.1
Operating leases	14.5	19.4
Other long-term liabilities	283.1	258.7
Crestwood Midstream Partners LP
Accrued Expenses and Other Liabilities [Line Items]
Accrued expenses	50.0	66.3
Accrued property taxes	5.2	4.4
Income tax payable	0.4	0.4
Interest payable	54.7	30.6
Accrued additions to property, plant and equipment	25.6	17.4
Operating leases	10.4	13.2
Finance leases	30.5	1.7
Contract liabilities	11.0	10.7
Asset retirement obligations	1.1	1.4
Total CMLP accrued expenses and other liabilities	188.9	146.1
Contract liabilities	202.1	187.1
Operating leases	14.5	19.4
Asset retirement obligations	51.7	34.8
Other long-term liabilities	281.6	254.1
Crestwood Midstream Partners LP | Other
Accrued Expenses and Other Liabilities [Line Items]
Other long-term liabilities	13.3	12.8
Crestwood Equity Partners LP
Accrued Expenses and Other Liabilities [Line Items]
Accrued expenses	1.2	0.9
Income tax payable	0.2	0.1
Total CMLP accrued expenses and other liabilities	190.3	147.1
Other long-term liabilities	283.1	258.7
Crestwood Equity Partners LP | Other
Accrued Expenses and Other Liabilities [Line Items]
Other long-term liabilities	$ 1.5	$ 4.6