Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net loss	$ (2,303.7)	$ (10.4)	$ (50.6)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, amortization and accretion	300.1	285.3	167.9
Amortization of debt-related deferred costs, discounts and premiums	8.9	8.5	9.2
Market adjustment on interest rate swaps	(0.5)	(2.7)	(1.7)
Unit-based compensation charges	19.7	21.3	17.4
Gain (loss) on long-lived assets, net	821.2	1.9	(5.3)
Goodwill impairment	1,406.3	48.8	4.1
Loss on contingent consideration	0.0	8.6	31.4
Loss on modification/extinguishment of debt	20.0	0.0	0.0
Loss from unconsolidated affiliates, net, adjusted for cash distributions received	73.6	0.7	0.1
Deferred income taxes	(3.6)	(5.2)	(2.8)
Other	0.7	0.0	(1.0)
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	119.7	60.4	(39.9)
Inventory	2.0	26.9	(23.6)
Prepaid expenses and other current assets	1.8	(11.4)	11.2
Accounts payable, accrued expenses and other liabilities	(128.0)	(96.4)	44.2
Reimbursements of property, plant and equipment	73.3	21.5	0.0
Change in price risk management activities, net	29.2	(74.8)	27.7
Net cash provided by operating activities	440.7	283.0	188.3
Investing activities
Acquisitions, net of cash acquired (Note 3)	0.0	(19.5)	(555.6)
Purchases of property, plant and equipment	(182.7)	(424.0)	(347.0)
Investment in unconsolidated affiliates	(42.0)	(108.6)	(151.5)
Capital distributions from unconsolidated affiliates	9.3	0.0	0.0
Proceeds from sale of Tres Palacios	0.0	66.4	0.0
Proceeds from sale of assets	2.7	2.7	11.2
Net cash used in investing activities	(212.7)	(483.0)	(1,042.9)
Financing activities
Proceeds from the issuance of long-term debt	4,261.8	2,823.9	2,466.9
Principal payments on long-term debt	(4,113.0)	(2,696.0)	(1,967.6)
Payments on capital leases	(2.2)	(3.2)	(4.3)
Payments for debt-related deferred costs	(17.3)	(1.9)	(33.1)
Financing fees paid for early debt redemption	13.6	0.0	0.0
Distributions to partners	(171.5)	(102.5)	(68.4)
Distributions paid to non-controlling partners	(234.2)	(296.5)	(204.5)
Distribution for additional interest in Crestwood Marcellus Midstream LLC	0.0	0.0	(129.0)
Net proceeds from issuance of Crestwood Midstream Partners LP common units	0.0	0.0	714.0
Net proceeds from issuance of preferred equity of subsidiary	0.0	53.9	96.1
Issuance of CMLP Class A preferred units	(58.8)
Taxes paid for unit-based compensation vesting	(3.8)	(3.9)	(10.5)
Other	(1.3)	(0.7)	0.1
Net cash provided by (used in) financing activities	(236.3)	203.6	859.7
Net change in cash	(8.3)	3.6	5.1
Cash at beginning of period	8.8	5.2	0.1
Cash at end of period	0.5	8.8	5.2
Cash paid during the period for interest	129.0	114.4	64.9
Cash paid during the period for income taxes	4.7	6.6	2.5
Supplemental schedule of noncash investing and financing activities
Net change to property, plant and equipment through accounts payable and accrued expenses	(14.1)	(40.6)	(38.0)
Acquisitions, net of cash acquired:
Current assets		0.5	409.6
Property, plant and equipment		13.5	2,487.2
Intangible assets		9.4	660.9
Goodwill		3.6	2,195.4
Other assets		0.0	32.1
Current liabilities		(2.7)	(420.6)
Debt		(3.5)	(1,079.3)
Invested capital of Crestwood Equity Partners LP, net of debt (Note 3)		0.0	(3,579.4)
Other liabilities		(1.3)	(150.3)
Total acquisitions, net of cash acquired		19.5	555.6
Preferred Units, Class A
Financing activities
Net proceeds from issuance of preferred equity of subsidiary	58.8	430.5	0.0
CMLP
Operating activities
Net loss	(1,410.6)	14.7	(12.4)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, amortization and accretion	278.5	255.4	139.4
Amortization of debt-related deferred costs, discounts and premiums	8.1	7.3	9.1
Unit-based compensation charges	18.1	18.1	15.8
Gain (loss) on long-lived assets, net	227.8	35.1	(5.3)
Goodwill impairment	1,149.1	48.8	4.1
Loss on contingent consideration	0.0	8.6	31.4
Loss on modification/extinguishment of debt	18.9	0.0	0.0
Loss from unconsolidated affiliates, net, adjusted for cash distributions received	73.6	0.7	0.1
Deferred income taxes	(0.3)	0.7	0.0
Other	0.7	0.0	0.1
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	119.4	60.4	(39.9)
Inventory	2.1	26.9	(23.6)
Prepaid expenses and other current assets	3.7	(11.9)	5.9
Accounts payable, accrued expenses and other liabilities	(119.8)	25.8	101.3
Reimbursements of property, plant and equipment	73.3	21.5	0.0
Change in price risk management activities, net	29.2	(74.8)	27.7
Net cash provided by operating activities	471.8	437.3	253.7
Investing activities
Acquisitions, net of cash acquired (Note 3)	0.0	(19.5)	(561.5)
Purchases of property, plant and equipment	(182.7)	(421.7)	(339.3)
Investment in unconsolidated affiliates	(41.8)	(144.4)	(151.5)
Capital distributions from unconsolidated affiliates	9.3	0.0	0.0
Proceeds from sale of Tres Palacios	9.3
Proceeds from sale of assets	2.7	2.7	11.2
Net cash used in investing activities	(212.5)	(582.9)	(1,041.1)
Financing activities
Proceeds from the issuance of long-term debt	3,490.1	2,089.9	2,072.8
Principal payments on long-term debt	(2,960.9)	(1,950.0)	(1,634.5)
Payments on capital leases	(2.2)	(3.2)	(4.3)
Payments for debt-related deferred costs	(17.3)	(0.1)	(32.0)
Financing fees paid for early debt redemption	(13.6)	0.0	0.0
Distributions to partners	(819.5)	(470.5)	(419.7)
Distributions paid to non-controlling partners	0.0	0.0	5.5
Contributions from general partner	0.0	0.0	5.5
Net proceeds from issuance of Crestwood Midstream Partners LP common units	0.0	0.0	714.0
Net proceeds from issuance of preferred equity of subsidiary	0.0	53.9	96.1
Issuance of CMLP Class A preferred units	58.8	430.5
Taxes paid for unit-based compensation vesting	(2.1)	(1.6)	(5.5)
Other	(0.1)	(0.8)	0.0
Net cash provided by (used in) financing activities	(266.8)	148.1	792.4
Net change in cash	(7.5)	2.5	5.0
Cash at beginning of period	7.6	5.1	0.1
Cash at end of period	0.1	7.6	5.1
Cash paid during the period for interest	118.2	96.9	56.7
Cash paid during the period for income taxes	0.6	0.4	0.0
Supplemental schedule of noncash investing and financing activities
Net change to property, plant and equipment through accounts payable and accrued expenses	(14.1)	(40.6)	(30.5)
Acquisitions, net of cash acquired:
Current assets		0.5	240.0
Property, plant and equipment		13.5	2,076.8
Intangible assets		9.4	519.4
Goodwill		3.6	1,583.2
Other assets		0.0	22.3
Current liabilities		(2.7)	(243.9)
Debt		(3.5)	(745.0)
Invested capital of Crestwood Equity Partners LP, net of debt (Note 3)		0.0	(2,882.3)
Other liabilities		(1.3)	(9.0)
Total acquisitions, net of cash acquired		19.5	561.5
CMLP | Preferred Units, Class A
Financing activities
Issuance of CMLP Class A preferred units	$ 58.8	$ 430.5	$ 0.0