Consolidated Statement of Partners' Capital - USD ($) $ in Millions	Total	Preferred Units	Common unit	Partners' Capital	Crestwood Midstream Partners LP	Crestwood Midstream Partners LP Partners' Capital	Preferred Units	Common Units	Subordinated Units	Common Stock
Preferred units, beginning balance (in units) at Dec. 31, 2020							71,300,000
Partner units, beginning balance (in units) at Dec. 31, 2020								73,600,000	400,000
Beginning balance at Dec. 31, 2020		$ 612.0	$ 1,043.4	$ 1,655.4		$ 1,805.1
Increase (Decrease) in Partners' Capital [Roll Forward]
Stock Repurchased and Retired During Period, Value			(273.2)	(273.2)
Retirement of common units (in units)								(11,500,000)	(400,000)
Distributions to partners		(15.0)	(46.4)	(61.4)		(334.0)
Unit-based compensation charges (in shares)								1,100,000
Unit-based compensation charges			3.7	3.7		2.3
Taxes paid for unit-based compensation vesting (in shares)								(400,000)
Taxes paid for unit-based compensation vesting			(8.1)	(8.1)		(8.1)
Other			(0.4)	(0.4)		(0.1)
Net income (loss) attributable to parent		15.0	(63.4)	(48.4)		(50.5)
Preferred units, ending balance (in units) at Mar. 31, 2021							71,300,000
Partner units, ending balance (in units) at Mar. 31, 2021								62,800,000	0
Ending Balance at Mar. 31, 2021		612.0	655.6	1,267.6		1,414.7
Preferred units, beginning balance (in units) at Dec. 31, 2020							71,300,000
Partner units, beginning balance (in units) at Dec. 31, 2020								73,600,000	400,000
Beginning balance at Dec. 31, 2020		612.0	1,043.4	1,655.4		1,805.1
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss) attributable to parent	$ (146.7)				$ (151.4)
Preferred units, ending balance (in units) at Sep. 30, 2021							71,300,000
Partner units, ending balance (in units) at Sep. 30, 2021								62,900,000	0
Ending Balance at Sep. 30, 2021		612.0	464.3	1,076.3		1,213.5
Preferred units, beginning balance (in units) at Mar. 31, 2021							71,300,000
Partner units, beginning balance (in units) at Mar. 31, 2021								62,800,000	0
Beginning balance at Mar. 31, 2021		612.0	655.6	1,267.6		1,414.7
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.0)	(39.3)	(54.3)		(61.4)
Unit-based compensation charges			7.6	7.6		7.6
Taxes paid for unit-based compensation vesting (in shares)								0
Taxes paid for unit-based compensation vesting			(0.1)	(0.1)		(0.1)
Other			(0.3)	(0.3)
Net income (loss) attributable to parent		15.0	(63.4)	(48.4)		(48.8)
Preferred units, ending balance (in units) at Jun. 30, 2021							71,300,000
Partner units, ending balance (in units) at Jun. 30, 2021								62,800,000	0
Ending Balance at Jun. 30, 2021		612.0	560.1	1,172.1		1,312.0
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.0)	(39.3)	(54.3)		(55.9)
Unit-based compensation charges (in shares)								100,000
Unit-based compensation charges			9.6	9.6		9.6
Taxes paid for unit-based compensation vesting			(0.1)	(0.1)		(0.1)
Other			(1.1)	(1.1)
Net income (loss) attributable to parent	$ (49.9)	15.0	(64.9)	(49.9)	(52.1)	(52.1)
Preferred units, ending balance (in units) at Sep. 30, 2021							71,300,000
Partner units, ending balance (in units) at Sep. 30, 2021								62,900,000	0
Ending Balance at Sep. 30, 2021		612.0	464.3	1,076.3		1,213.5
Preferred units, beginning balance (in units) at Dec. 31, 2021	71,257,445						71,300,000
Partner units, beginning balance (in units) at Dec. 31, 2021								63,000,000.0
Beginning balance at Dec. 31, 2021		612.0	487.6	1,099.6	1,232.3	1,232.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.0)	(60.9)	(75.9)		(238.1)
Issuance of common units (in shares)										33,800,000
Issuance of common units (Note 3)			930.0	930.0
Non-cash contribution from partner (Note 11)						1,075.1
Cash contribution from partner (Note 11)						14.9
Unit-based compensation charges (in shares)								1,600,000
Unit-based compensation charges			13.0	13.0		13.0
Taxes paid for unit-based compensation vesting (in shares)								(500,000)
Taxes paid for unit-based compensation vesting			(14.9)	(14.9)		(14.9)
Other (in shares)	100,000
Other			2.2	2.2		0.1
Net income (loss) attributable to parent		15.0	(3.0)	12.0		10.0
Preferred units, ending balance (in units) at Mar. 31, 2022							71,300,000
Partner units, ending balance (in units) at Mar. 31, 2022								98,000,000.0
Ending Balance at Mar. 31, 2022		612.0	1,354.0	1,966.0		2,092.4
Preferred units, beginning balance (in units) at Dec. 31, 2021	71,257,445						71,300,000
Partner units, beginning balance (in units) at Dec. 31, 2021								63,000,000.0
Beginning balance at Dec. 31, 2021		612.0	487.6	1,099.6	1,232.3	1,232.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss) attributable to parent	$ (12.2)				(138.2)
Preferred units, ending balance (in units) at Sep. 30, 2022	71,257,445						71,300,000
Partner units, ending balance (in units) at Sep. 30, 2022								104,700,000
Ending Balance at Sep. 30, 2022		612.0	1,326.2	1,938.2	1,937.1	1,937.1
Preferred units, beginning balance (in units) at Mar. 31, 2022							71,300,000
Partner units, beginning balance (in units) at Mar. 31, 2022								98,000,000.0
Beginning balance at Mar. 31, 2022		612.0	1,354.0	1,966.0		2,092.4
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.0)	(64.2)	(79.2)		(81.6)
Unit-based compensation charges			8.6	8.6		8.6
Taxes paid for unit-based compensation vesting			(0.7)	(0.7)		(0.7)
Other			(0.4)	(0.4)
Net income (loss) attributable to parent		15.0	14.1	29.1		(24.9)
Preferred units, ending balance (in units) at Jun. 30, 2022							71,300,000
Partner units, ending balance (in units) at Jun. 30, 2022								98,000,000.0
Ending Balance at Jun. 30, 2022		612.0	1,311.4	1,923.4		1,993.8
Increase (Decrease) in Partners' Capital [Roll Forward]
Retirement of common units (in units)								(4,600,000)
Distributions to partners		(15.0)	(71.6)	(86.6)		(217.9)
Issuance of common units (in shares)										11,300,000
Issuance of common units (Note 3)			270.8	270.8
Purchase of common units (Note 11)			(123.7)	(123.7)
Non-cash contribution from partner (Note 11)						127.3
Cash contribution from partner (Note 11)						149.4
Unit-based compensation charges			8.0	8.0		8.0
Taxes paid for unit-based compensation vesting			(0.2)	(0.2)		(0.2)
Other			(0.2)	(0.2)
Net income (loss) attributable to parent	$ (53.3)	15.0	(68.3)	(53.3)	(123.3)	(123.3)
Preferred units, ending balance (in units) at Sep. 30, 2022	71,257,445						71,300,000
Partner units, ending balance (in units) at Sep. 30, 2022								104,700,000
Ending Balance at Sep. 30, 2022		$ 612.0	$ 1,326.2	$ 1,938.2	$ 1,937.1	$ 1,937.1