Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred:
Total deferred	$ 0.4	$ (0.1)	$ 0.0
(Provision) benefit for income taxes	(0.2)	(0.4)	(0.3)
Crestwood Equity Partners LP
Income Tax Contingency [Line Items]
Deferred Tax Assets, Gross	0.2	0.2
Current:
Federal	(0.4)	(0.2)	(0.1)
State	(0.2)	(0.1)	(0.2)
Total current	(0.6)	(0.3)	(0.3)
Deferred:
Federal	0.3	(0.1)	0.1
State	0.1	0.0	(0.1)
Total deferred	0.4	(0.1)	0.0
(Provision) benefit for income taxes	(0.2)	(0.4)	(0.3)
Deferred Tax Assets, Net [Abstract]
Total deferred tax liability	(2.5)	(2.9)
Deferred Tax Liabilities, Net [Abstract]
Total deferred tax liability(1)	(2.3)	(2.7)
CMLP
Income Tax Contingency [Line Items]
Deferred Tax Assets, Gross	0.0	0.0
Current:
Federal	0.0	0.1	0.1
State	(0.1)	0.0	(0.2)
Total current	(0.1)	0.1	(0.1)
Deferred:
Federal	0.0	0.0	0.0
State	0.0	0.0	(0.2)
Total deferred	0.0	0.0	(0.2)
(Provision) benefit for income taxes	(0.1)	0.1	$ (0.3)
Deferred Tax Assets, Net [Abstract]
Total deferred tax liability	(0.8)	(0.7)
Deferred Tax Liabilities, Net [Abstract]
Total deferred tax liability(1)	$ (0.8)	$ (0.7)