Segments (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Revenue, Major Customer [Line Items]
Revenues	$ 4,569.0	$ 2,254.3	$ 3,181.9
Number of operating segments | segment	3
Crestwood Equity Partners LP
Revenue, Major Customer [Line Items]
Earnings (Losses) Before Interest, Taxes, Depreciation and Amortization from Equity Method Investments	$ 187.4	42.9	42.1
CMLP
Revenue, Major Customer [Line Items]
Revenues	$ 4,569.0	$ 2,254.3	3,181.9
British Petroleum and its subsidiaries
Revenue, Major Customer [Line Items]
Revenues			$ 333.9