Partners' Capital Net Income (Loss) Attributable to NonControlling Partners (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Limited Partners' Capital Account [Line Items]
Net income (loss) attributable to non-controlling partners in subsidiary	$ 16.2	$ 25.3	$ 24.2
CMLP
Limited Partners' Capital Account [Line Items]
Net income (loss) attributable to non-controlling partners in subsidiary	16.2	25.3	24.2
Crestwood Niobrara LLC
Limited Partners' Capital Account [Line Items]
Net income (loss) attributable to non-controlling partners in subsidiary	$ 16.2	$ 25.3	$ 24.2