Earnings Per Limited Partner Unit (Schedule of Reconciliation of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Allocated to Limited Partners	$ 223.6	$ (9.3)	$ (254.4)
Subordinated unitholders’ interest in net income	1.4	0.0	0.0
Net Income (Loss) Available to Common Stockholders, Diluted	$ 225.0	$ (9.3)	$ (254.4)
Basic (units)	71.8	71.2	69.8
Dilutive units (units)	5.1	0.0	0.0
Weighted Average Limited Partnership Units Outstanding, Diluted	76.9	71.2	69.8
Earnings Per Share, Basic	$ 3.11	$ (0.13)	$ (3.64)
Earnings Per Share, Diluted	$ 2.93	$ (0.13)	$ (3.64)
Niobrara Preferred Units [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive units (units)	4.3	0.0	0.0
Preferred Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share	7.1	7.1	7.0
Subordinated units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share	0.0	0.4	0.4
Dilutive units (units)	0.4	0.0	0.0
Performance Shares
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share	0.0	0.4	0.3
Dilutive units (units)	0.4	0.0	0.0
Crestwood Niobrara LLC | Preferred Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share	0.0	6.5	7.1