Consolidated Statement of Partners' Capital - USD ($) $ in Millions	Total	Preferred Units	Common unit	Non-Controlling Partners	Partners' Capital	Crestwood Midstream Partners LP	Crestwood Midstream Partners LP Common unit	Crestwood Midstream Partners LP Non-Controlling Partners	Crestwood Midstream Partners LP Partners' Capital	Common Units	Preferred Units	Subordinated Units
Common Unit, Outstanding										69,100,000		400,000
Preferred Units, Outstanding	66,533,415										66,500,000
Preferred Stock Dividends, Shares	4,724,030										4,800,000
Balance at December 31, 2016 at Dec. 31, 2016	$ 2,346.5	$ 564.5	$ 1,782.0	$ 192.5	$ 2,539.0	$ 2,550.7	$ 2,550.7	$ 192.5	$ 2,743.2
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		0.0	(125.4)	(11.4)	(136.8)	(130.9)	(119.5)	(11.4)	(130.9)
Change in fair value of Suburban Propane Partners, L.P. units	(0.6)	0.0	(0.6)	0.0	(0.6)
Partners' Capital Account, Sale of Units		0.0	10.6	0.0	10.6
Partners' Capital Account, Units, Sold in Public Offering										400,000
Unit-based compensation charges		0.0	18.9	0.0	18.9		18.9	0.0	18.9
Partners' Capital Account, Units, Unit-based Compensation										900,000
Taxes paid for unit-based compensation vesting		0.0	(5.3)	0.0	(5.3)		(5.3)	0.0	(5.3)
Shares Paid for Tax Withholding for Share Based Compensation										(200,000)
Other		0.0	(0.5)	0.0	(0.5)		(0.5)	0.0	(0.5)
Net income (loss) attributable to preferred unit holders	47.5	47.5
Net loss attributable to partners	(113.3)		(113.3)
Net Income (Loss) Attributable to Noncontrolling Interest	18.8			18.8		18.8
Net income (loss)	(47.0)				(47.0)	(53.1)	(71.9)		(53.1)
Balance at September 30, 2017 at Sep. 30, 2017	$ 2,178.4	$ 612.0	$ 1,566.4	$ 199.9	$ 2,378.3	$ 2,372.4	$ 2,372.4	$ 199.9	$ 2,572.3
Common Unit, Outstanding										70,200,000		400,000
Preferred Units, Outstanding	71,257,445										71,300,000