Certain Balance Sheet Information (Accrued Expenses and Other Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Accrued Expenses and Other Liabilities [Line Items]
Operating leases	$ 13.2	$ 14.7
Finance leases	1.7	2.9
Contract liabilities	10.7	10.3
Asset retirement obligations	1.4	1.0
Accrued expenses and other liabilities	147.1	122.0
CMLP
Accrued Expenses and Other Liabilities [Line Items]
Accrued expenses	66.3	45.4
Accrued property taxes	4.4	8.4
Income tax payable	0.4	0.2
Interest payable	30.6	24.9
Accrued additions to property, plant and equipment	17.4	12.3
Operating leases	13.2	14.7
Finance leases	1.7	2.9
Contract liabilities	10.7	10.3
Asset retirement obligations	1.4	1.0
Accrued expenses and other liabilities	146.1	120.1
Crestwood Equity Partners LP
Accrued Expenses and Other Liabilities [Line Items]
Accrued expenses	0.9	1.9
Income tax payable	0.1	0.0
Accrued expenses and other liabilities	$ 147.1	$ 122.0