Condensed Consolidating Financial Information (Statements Of Operations) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues	$ 587.6		$ 630.7	$ 1,725.5	$ 2,003.7
Total costs of products/services sold	466.7		449.2	1,280.1	1,438.4
Expenses:
Operations and maintenance	33.1		49.3	119.9	143.8
General and administrative	18.3		32.8	70.2	90.9
Depreciation, amortization and accretion	50.3		75.5	177.0	224.5
Loss on long-lived assets, net	(2.1)		(2.3)	(34.8)	(3.9)
Goodwill impairment	0.0	$ (109.7)	(609.9)	(109.7)	(890.9)
Operating loss	17.1		(588.3)	(66.2)	(788.7)
Earnings from unconsolidated affiliates, net	13.4		2.8	26.1	11.2
Interest and debt expense, net	(27.5)		(35.7)	(97.9)	(104.7)
Loss before income taxes	3.2		(623.7)	(127.6)	(901.5)
(Provision) benefit for income taxes	(0.2)		0.3	(0.2)	0.2
Net loss	3.0		(623.4)	(127.8)	(901.3)
Net income attributable to non-controlling partners in subsidiaries	6.1		(396.5)	18.0	(642.7)
Net income (loss) attributable to parent	(3.1)		(226.9)	(145.8)	(258.6)
Net income (loss) attributable to preferred unit holders	6.9		0.0	16.6	0.0
Net loss attributable to partners	(10.0)		(226.9)	(162.4)	(258.6)
Gains (Losses) on Extinguishment of Debt	0.0		(2.7)	10.0	(19.8)
Eliminations
Revenues	0.0		0.0	0.0	0.0
Total costs of products/services sold	0.0		0.0	0.0	0.0
Expenses:
Operations and maintenance	0.0		0.0	0.0	0.0
General and administrative	0.0		0.0	0.0	0.0
Depreciation, amortization and accretion	0.0		0.0	0.0	0.0
Costs and Expenses	0.0		0.0	0.0	0.0
Loss on long-lived assets, net	0.0		0.0	0.0	0.0
Goodwill impairment			0.0	0.0	0.0
Operating loss	0.0		0.0	0.0	0.0
Earnings from unconsolidated affiliates, net	0.0		0.0	0.0	0.0
Interest and debt expense, net	0.0		0.0	0.0	0.0
Loss from unconsolidated affiliates	(41.4)		554.1	(11.8)	487.3
Loss before income taxes			554.1		487.3
(Provision) benefit for income taxes			0.0		0.0
Net loss	(41.4)		554.1	(11.8)	487.3
Net income attributable to non-controlling partners in subsidiaries	0.0		0.0	0.0	0.0
Net income (loss) attributable to parent	(41.4)		554.1	(11.8)	487.3
Net income (loss) attributable to preferred unit holders			0.0		0.0
Net loss attributable to partners			554.1		487.3
Gains (Losses) on Extinguishment of Debt			0.0	0.0	0.0
Parent Company, Crestwood Midstream Partners, LP | Reportable Legal Entities
Revenues	0.0		0.0	0.0	0.0
Total costs of products/services sold	0.0		0.0	0.0	0.0
Expenses:
Operations and maintenance	0.0		0.0	0.0	0.0
General and administrative	13.3		21.2	54.2	51.0
Depreciation, amortization and accretion	0.0		0.5	0.0	1.6
Costs and Expenses	13.3		21.7	54.2	52.6
Loss on long-lived assets, net	0.0		0.0	0.0	0.0
Goodwill impairment			0.0	0.0	0.0
Operating loss	(13.3)		(21.7)	(54.2)	(52.6)
Earnings from unconsolidated affiliates, net	0.0		0.0	0.0	0.0
Interest and debt expense, net	(27.5)		(32.6)	(97.9)	(95.1)
Loss from unconsolidated affiliates	41.4		(554.1)	11.8	(487.3)
Loss before income taxes			(610.2)		(653.9)
(Provision) benefit for income taxes			0.0		0.0
Net loss	0.6		(610.2)	(130.3)	(653.9)
Net income attributable to non-controlling partners in subsidiaries	0.0		0.0	0.0	0.0
Net income (loss) attributable to parent	0.6		(610.2)	(130.3)	(653.9)
Net income (loss) attributable to preferred unit holders			6.4		23.1
Net loss attributable to partners			(616.6)		(677.0)
Gains (Losses) on Extinguishment of Debt			(1.8)	10.0	(18.9)
Guarantor Subsidiaries | Reportable Legal Entities
Revenues	587.6		630.7	1,725.5	2,003.7
Total costs of products/services sold	466.7		449.2	1,280.1	1,438.4
Expenses:
Operations and maintenance	33.6		48.8	116.7	143.3
General and administrative	4.0		8.0	13.3	31.1
Depreciation, amortization and accretion	53.2		69.5	185.2	206.7
Costs and Expenses	90.8		126.3	315.2	381.1
Loss on long-lived assets, net	(2.1)		(2.3)	(34.8)	(3.8)
Goodwill impairment			(609.9)	(109.7)	(678.5)
Operating loss	28.0		(557.0)	(14.3)	(498.1)
Earnings from unconsolidated affiliates, net	0.0		0.0	0.0	0.0
Interest and debt expense, net	0.0		0.0	0.0	0.0
Loss from unconsolidated affiliates	0.0		0.0	0.0	0.0
Loss before income taxes			(557.0)		(498.1)
(Provision) benefit for income taxes			0.1		(0.4)
Net loss	28.0		(556.9)	(14.3)	(498.5)
Net income attributable to non-controlling partners in subsidiaries	0.0		0.0	0.0	0.0
Net income (loss) attributable to parent	28.0		(556.9)	(14.3)	(498.5)
Net income (loss) attributable to preferred unit holders			0.0		0.0
Net loss attributable to partners			(556.9)		(498.5)
Gains (Losses) on Extinguishment of Debt			0.0	0.0	0.0
Non-Guarantor Subsidiaries | Reportable Legal Entities
Revenues	0.0		0.0	0.0	0.0
Total costs of products/services sold	0.0		0.0	0.0	0.0
Expenses:
Operations and maintenance	0.0		0.0	0.0	0.0
General and administrative	0.0		0.0	0.0	0.0
Depreciation, amortization and accretion	0.0		0.0	0.0	0.0
Costs and Expenses	0.0		0.0	0.0	0.0
Loss on long-lived assets, net	0.0		0.0	0.0	0.0
Goodwill impairment			0.0	0.0	0.0
Operating loss	0.0		0.0	0.0	0.0
Earnings from unconsolidated affiliates, net	13.4		2.8	26.1	11.2
Interest and debt expense, net	0.0		0.0	0.0	0.0
Loss from unconsolidated affiliates	0.0		0.0	0.0	0.0
Loss before income taxes			2.8		11.2
(Provision) benefit for income taxes			0.0		0.0
Net loss	13.4		2.8	26.1	11.2
Net income attributable to non-controlling partners in subsidiaries	6.1		5.9	18.0	17.2
Net income (loss) attributable to parent	7.3		(3.1)	8.1	(6.0)
Net income (loss) attributable to preferred unit holders			0.0		0.0
Net loss attributable to partners			(3.1)		(6.0)
Gains (Losses) on Extinguishment of Debt			0.0	0.0	0.0
Crestwood Midstream Partners LP
Revenues	587.6		630.7	1,725.5	2,003.7
Total costs of products/services sold	466.7		449.2	1,280.1	1,438.4
Expenses:
Operations and maintenance	33.6		48.8	116.7	143.3
General and administrative	17.3		29.2	67.5	82.1
Depreciation, amortization and accretion	53.2		70.0	185.2	208.3
Costs and Expenses	104.1		148.0	369.4	433.7
Loss on long-lived assets, net	(2.1)		(2.3)	(34.8)	(3.8)
Goodwill impairment	0.0		(609.9)	(109.7)	(678.5)
Operating loss	14.7		(578.7)	(68.5)	(550.7)
Earnings from unconsolidated affiliates, net	13.4		2.8	26.1	11.2
Interest and debt expense, net	(27.5)		(32.6)	(97.9)	(95.1)
Loss from unconsolidated affiliates	0.0		0.0	0.0	0.0
Loss before income taxes	0.6		(610.3)	(130.3)	(653.5)
(Provision) benefit for income taxes	0.0		0.1	0.0	(0.4)
Net loss	0.6		(610.2)	(130.3)	(653.9)
Net income attributable to non-controlling partners in subsidiaries	6.1		5.9	18.0	17.2
Net income (loss) attributable to parent	(5.5)		(616.1)	(148.3)	(671.1)
Net income (loss) attributable to preferred unit holders	0.0		6.4	0.0	23.1
Net loss attributable to partners	(5.5)		(622.5)	(148.3)	(694.2)
Gains (Losses) on Extinguishment of Debt	$ 0.0		$ (1.8)	$ 10.0	$ (18.9)