Partners' Capital (Schedule of Partners' Capital Account, Distriubtions) (Details) - USD ($) $ / shares in Units, $ in Millions							3 Months Ended
	Feb. 12, 2016	Feb. 05, 2016	Feb. 13, 2015	Feb. 06, 2015	Feb. 14, 2014	Feb. 07, 2014	Mar. 31, 2016	Mar. 31, 2015
Distribution Made to Limited Partner [Line Items]
Distribution Made to Limited Partner, Date of Record		Feb. 05, 2016		Feb. 06, 2015
Distribution Made to Limited Partner, Distribution Date	Feb. 12, 2016		Feb. 13, 2015
Distribution Made to Member or Limited Partner, Distributions Paid, Per Unit	$ 1.375		$ 1.375
Distribution Made to Limited Partner, Cash Distributions Paid	$ 95.6		$ 25.8				$ 97.2	$ 26.6
Crestwood Midstream Partners LP
Distribution Made to Limited Partner [Line Items]
Distribution Made to Limited Partner, Date of Record						Feb. 06, 2015
Distribution Made to Limited Partner, Distribution Date					Feb. 13, 2015
Distribution Made to Member or Limited Partner, Distributions Paid, Per Unit					$ 0.41
Distribution Made to Limited Partner, Cash Distributions Paid					$ 74.3