Basis of Presentation and Summary of Significant Accounting Policies (Details) $ in Millions	1 Months Ended	3 Months Ended				9 Months Ended		12 Months Ended
	Apr. 30, 2016 USD ($)	Sep. 30, 2016 USD ($) mi	Mar. 31, 2016 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) mi	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Miles of Pipeline | mi		37.5				37.5
Net proceeds from sale of assets	$ 945.0					$ 943.1	$ 2.9
Property Plant and Equipment Disposition						1,094.6
Increase (Decrease) in Intangible Assets, Current						8.5
Increase (Decrease) in Other Current Assets and Liabilities, Net						$ 10.9
Impaired Assets to be Disposed of by Method Other than Sale, Amount of Impairment Loss								$ 354.4
Percentage Disposition Exceeded Carrying Value Of Property Plant And Equipment		30.00%				30.00%		0.00%
Deferred Finance Costs, Net		$ 35.9				$ 35.9		$ 40.9
Goodwill [Roll Forward]
Goodwill at December 31, 2015			$ 1,085.5			1,085.5
Goodwill impairment		0.0	109.7	$ 609.9		109.7	890.9
Goodwill at September 30, 2016		249.5				249.5		1,085.5
Goodwill, Written off Related to Sale of Business Unit					$ 726.3
Fayetteville
Goodwill [Roll Forward]
Goodwill impairment				39.1			47.4
Marcellus
Goodwill [Roll Forward]
Goodwill at December 31, 2015			8.6			8.6
Goodwill impairment			8.6
Goodwill at September 30, 2016		0.0				0.0		8.6
Arrow
Goodwill [Roll Forward]
Goodwill at December 31, 2015			45.9			45.9
Goodwill impairment			0.0
Goodwill at September 30, 2016		45.9				45.9		45.9
Northeast Storage and Transportation
Goodwill [Roll Forward]
Goodwill at December 31, 2015			726.3			726.3
Goodwill impairment			0.0
Goodwill at September 30, 2016		0.0				0.0		726.3
Goodwill, Written off Related to Sale of Business Unit					$ 726.3
COLT
Goodwill [Roll Forward]
Goodwill at December 31, 2015			44.9			44.9
Goodwill impairment			13.7	348.0			348.0
Goodwill at September 30, 2016		31.2				31.2		44.9
Supply and Logistics
Goodwill [Roll Forward]
Goodwill at December 31, 2015			167.2			167.2
Goodwill impairment			65.5
Goodwill at September 30, 2016		101.7				101.7		167.2
Storage and Terminals
Goodwill [Roll Forward]
Goodwill at December 31, 2015			50.5			50.5
Goodwill impairment			14.1
Goodwill at September 30, 2016		36.4				36.4		50.5
US Salt
Goodwill [Roll Forward]
Goodwill at December 31, 2015			12.6			12.6
Goodwill impairment			0.0
Goodwill at September 30, 2016		12.6				12.6		12.6
Trucking
Goodwill [Roll Forward]
Goodwill at December 31, 2015			29.5			29.5
Goodwill impairment			7.8	147.3			147.3
Goodwill at September 30, 2016		21.7				$ 21.7		29.5
West Coast
Goodwill [Roll Forward]
Goodwill impairment				57.5			85.9
Watkins Glen
Goodwill [Roll Forward]
Goodwill impairment				18.0			49.9
Barnett
Goodwill [Roll Forward]
Goodwill impairment				0.0			212.4
Minimum
Summary Of Significant Accounting Policies [Line Items]
Fair Value Inputs, Discount Rate						10.00%
Maximum
Summary Of Significant Accounting Policies [Line Items]
Fair Value Inputs, Discount Rate						19.00%
Crestwood Midstream Partners LP
Summary Of Significant Accounting Policies [Line Items]
Net proceeds from sale of assets						$ 943.1	2.9
Goodwill [Roll Forward]
Goodwill at December 31, 2015			$ 1,085.5			1,085.5
Goodwill impairment		0.0		$ 609.9		109.7	$ 678.5
Goodwill at September 30, 2016		$ 249.5				249.5		$ 1,085.5
CEGP
Summary Of Significant Accounting Policies [Line Items]
Net proceeds from sale of assets						$ 30.0
Ownership Percentage	50.00%	50.00%				50.00%