Condensed Consolidating Financial Information (Statements Of Operations) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues	$ 536.0	$ 731.5
Total costs of products/services sold	363.4	529.7
Expenses:
Operations and maintenance	41.8	50.6
General and administrative	23.0	27.5
Depreciation, amortization and accretion	62.3	74.2
Goodwill impairment	(109.7)	0.0
Operating income (loss)	(64.2)	48.5
Earnings from unconsolidated affiliates, net	6.5	3.4
Interest and debt expense, net	(36.1)	(33.6)
Loss before income taxes	(93.7)	18.5
Provision for income taxes	0.0	0.4
Net income (loss)	(93.7)	18.1
Net income attributable to non-controlling partners in subsidiaries	5.9	9.8
Net income (loss) attributable to parent	(99.6)	8.3
Net income (loss) attributable to preferred unit holders	1.6	0.0
Net income (loss) attributable to partners	(101.2)	8.3
Crestwood Midstream Partners LP
Revenues	536.0	731.5
Total costs of products/services sold	363.4	529.7
Expenses:
Operations and maintenance	41.7	50.6
General and administrative	22.2	25.6
Depreciation, amortization and accretion	64.9	68.8
Costs and Expenses	128.8	145.0
Loss on long-lived assets, net		(0.8)
Goodwill impairment	(109.7)	0.0
Operating income (loss)	(65.9)	56.0
Earnings from unconsolidated affiliates, net	6.5	3.4
Interest and debt expense, net	(36.1)	(29.9)
Loss from unconsolidated affiliates	0.0	0.0
Loss before income taxes	(95.5)	29.5
Provision for income taxes	(0.2)	0.4
Net income (loss)	(95.3)	29.1
Net income attributable to non-controlling partners in subsidiaries	5.9	5.6
Net income (loss) attributable to parent	(101.2)	23.5
Net income (loss) attributable to preferred unit holders	0.0	9.2
Net income (loss) attributable to partners	(101.2)	14.3
Crestwood Midstream Partners LP | Parent Company
Revenues	0.0	0.0
Total costs of products/services sold	0.0	0.0
Expenses:
Operations and maintenance	0.0	0.0
General and administrative	17.7	13.4
Depreciation, amortization and accretion	0.0	0.2
Costs and Expenses	17.7	13.6
Loss on long-lived assets, net		0.0
Goodwill impairment	0.0
Operating income (loss)	(17.7)	(13.6)
Earnings from unconsolidated affiliates, net	0.0	0.0
Interest and debt expense, net	(36.1)	(29.9)
Loss from unconsolidated affiliates	(41.5)	72.6
Loss before income taxes	(95.3)	29.1
Provision for income taxes	0.0	0.0
Net income (loss)	(95.3)	29.1
Net income attributable to non-controlling partners in subsidiaries	0.0	0.0
Net income (loss) attributable to parent	(95.3)	29.1
Net income (loss) attributable to preferred unit holders		9.2
Net income (loss) attributable to partners		19.9
Crestwood Midstream Partners LP | Guarantor Subsidiaries
Revenues	536.0	731.5
Total costs of products/services sold	363.4	529.7
Expenses:
Operations and maintenance	41.7	50.6
General and administrative	4.5	12.2
Depreciation, amortization and accretion	64.9	68.6
Costs and Expenses	111.1	131.4
Loss on long-lived assets, net		(0.8)
Goodwill impairment	(109.7)
Operating income (loss)	(48.2)	69.6
Earnings from unconsolidated affiliates, net	0.0	0.0
Interest and debt expense, net	0.0	0.0
Loss from unconsolidated affiliates	0.0	0.0
Loss before income taxes	(48.2)	69.6
Provision for income taxes	(0.2)	0.4
Net income (loss)	(48.0)	69.2
Net income attributable to non-controlling partners in subsidiaries	0.0	0.0
Net income (loss) attributable to parent	(48.0)	69.2
Net income (loss) attributable to preferred unit holders		0.0
Net income (loss) attributable to partners		69.2
Crestwood Midstream Partners LP | Non-Guarantor Subsidiaries
Revenues	0.0	0.0
Total costs of products/services sold	0.0	0.0
Expenses:
Operations and maintenance	0.0	0.0
General and administrative	0.0	0.0
Depreciation, amortization and accretion	0.0	0.0
Costs and Expenses	0.0	0.0
Loss on long-lived assets, net		0.0
Goodwill impairment	0.0
Operating income (loss)	0.0	0.0
Earnings from unconsolidated affiliates, net	6.5	3.4
Interest and debt expense, net	0.0	0.0
Loss from unconsolidated affiliates	0.0	0.0
Loss before income taxes	6.5	3.4
Provision for income taxes	0.0	0.0
Net income (loss)	6.5	3.4
Net income attributable to non-controlling partners in subsidiaries	5.9	5.6
Net income (loss) attributable to parent	0.6	(2.2)
Net income (loss) attributable to preferred unit holders		0.0
Net income (loss) attributable to partners		(2.2)
Crestwood Midstream Partners LP | Eliminations
Revenues	0.0	0.0
Total costs of products/services sold	0.0	0.0
Expenses:
Operations and maintenance	0.0	0.0
General and administrative	0.0	0.0
Depreciation, amortization and accretion	0.0	0.0
Costs and Expenses	0.0	0.0
Loss on long-lived assets, net		0.0
Goodwill impairment	0.0
Operating income (loss)	0.0	0.0
Earnings from unconsolidated affiliates, net	0.0	0.0
Interest and debt expense, net	0.0	0.0
Loss from unconsolidated affiliates	41.5	(72.6)
Loss before income taxes	41.5	(72.6)
Provision for income taxes	0.0	0.0
Net income (loss)	41.5	(72.6)
Net income attributable to non-controlling partners in subsidiaries	0.0	0.0
Net income (loss) attributable to parent	$ 41.5	(72.6)
Net income (loss) attributable to preferred unit holders		0.0
Net income (loss) attributable to partners		$ (72.6)