Fair Value Measurements (Schedule of Carrying Values and Estimated Fair Values of Senior Notes) (Details) - Crestwood Midstream Senior Notes - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
2023 Senior Notes
Debt Instrument [Line Items]
Carrying Amount	$ 0.0	$ 687.2
2023 Senior Notes | CMLP
Debt Instrument [Line Items]
Carrying Amount	0.0	683.8
Fair Value	0.0	691.5
2025 Senior Notes
Debt Instrument [Line Items]
Carrying Amount	500.0	500.0
2025 Senior Notes | CMLP
Debt Instrument [Line Items]
Carrying Amount	496.5	495.5
Fair Value	511.9	509.9
2027 Senior Notes | CMLP
Debt Instrument [Line Items]
Carrying Amount	594.2	593.2
Fair Value	615.0	594.1
2029 Senior Notes | CMLP
Debt Instrument [Line Items]
Carrying Amount	690.8	0.0
Fair Value	$ 727.3	$ 0.0