Certain Balance Sheet Information (Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 1,126.1	$ 1,126.1
Less: accumulated amortization	393.2	331.8
Total intangible assets, net	732.9	794.3
Customer accounts
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	488.7	488.7
Less: accumulated amortization	183.2	158.5
Customer accounts | Jackalope Gas Gathering Services, LLC
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross		49.8
Revenue contracts
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	631.2	631.2
Less: accumulated amortization	204.6	168.6
Trademarks
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	6.2	6.2
Less: accumulated amortization	5.4	4.7
Crestwood Equity Partners LP
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	61.4	60.7	$ 54.6
CMLP
Finite-Lived Intangible Assets [Line Items]
Less: accumulated amortization	$ 393.2	$ 331.8