Certain Balance Sheet Information (Other Long-Term Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Contract liabilities	$ 187.1	$ 172.2
Operating leases	19.4	28.5
Asset retirement obligations	34.8	34.1
Other long-term liabilities	258.7	253.3
CMLP
Other long-term liabilities	254.1	251.8
Crestwood Equity Partners LP
Other long-term liabilities	258.7	253.3
Other | CMLP
Other long-term liabilities	12.8	17.0
Other | Crestwood Equity Partners LP
Other long-term liabilities	$ 4.6	$ 1.5