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	Common Stock
Preferred units, beginning balance (in units) at Dec. 31, 2021							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
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
Unit-based compensation charges (in shares)								1,600,000
Unit-based compensation			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							71,300,000
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
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							71,300,000
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
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			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]
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)
Retirement of common units (Note 11) (in shares)								(4,600,000)
Unit-based compensation			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							71,300,000
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
Preferred units, beginning balance (in units) at Dec. 31, 2022	71,257,445						71,300,000
Partner units, beginning balance (in units) at Dec. 31, 2022								104,600,000
Beginning balance at Dec. 31, 2022		612.0	1,295.2	1,907.2	1,907.3	1,907.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.0)	(68.9)	(83.9)		(85.9)
Unit-based compensation charges (in shares)								1,100,000
Unit-based compensation			11.8	11.8		11.8
Taxes paid for unit-based compensation vesting (in shares)								(500,000)
Taxes paid for unit-based compensation vesting			(14.8)	(14.8)		(14.8)
Other (in shares)								100,000
Other			1.6	1.6
Net income (loss) attributable to parent		15.0	16.4	31.4		32.8
Preferred units, ending balance (in units) at Mar. 31, 2023							71,300,000
Partner units, ending balance (in units) at Mar. 31, 2023								105,300,000
Ending Balance at Mar. 31, 2023		612.0	1,241.3	1,853.3		1,851.2
Preferred units, beginning balance (in units) at Dec. 31, 2022	71,257,445						71,300,000
Partner units, beginning balance (in units) at Dec. 31, 2022								104,600,000
Beginning balance at Dec. 31, 2022		612.0	1,295.2	1,907.2	1,907.3	1,907.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss) attributable to parent	$ 153.0				165.2
Preferred units, ending balance (in units) at Sep. 30, 2023	71,257,445						71,300,000
Partner units, ending balance (in units) at Sep. 30, 2023								105,100,000
Ending Balance at Sep. 30, 2023		612.0	1,204.4	1,816.4	1,814.7	1,814.7
Preferred units, beginning balance (in units) at Mar. 31, 2023							71,300,000
Partner units, beginning balance (in units) at Mar. 31, 2023								105,300,000
Beginning balance at Mar. 31, 2023		612.0	1,241.3	1,853.3		1,851.2
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.0)	(68.9)	(83.9)		(85.4)
Unit-based compensation			9.2	9.2		9.2
Taxes paid for unit-based compensation vesting (in shares)								(100,000)
Taxes paid for unit-based compensation vesting			(0.8)	(0.8)		(0.8)
Other			(0.2)	(0.2)
Net income (loss) attributable to parent		15.0	126.6	141.6		143.1
Preferred units, ending balance (in units) at Jun. 30, 2023							71,300,000
Partner units, ending balance (in units) at Jun. 30, 2023								105,200,000
Ending Balance at Jun. 30, 2023		612.0	1,307.2	1,919.2		1,917.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Distributions to partners		(15.1)	(68.9)	(84.0)		(93.5)
Unit-based compensation			6.5	6.5		6.5
Taxes paid for unit-based compensation vesting (in shares)								(100,000)
Taxes paid for unit-based compensation vesting			(4.9)	(4.9)		(4.9)
Other			(0.4)	(0.4)
Net income (loss) attributable to parent	$ (20.0)	15.1	(35.1)	(20.0)	(10.7)	(10.7)
Preferred units, ending balance (in units) at Sep. 30, 2023	71,257,445						71,300,000
Partner units, ending balance (in units) at Sep. 30, 2023								105,100,000
Ending Balance at Sep. 30, 2023		$ 612.0	$ 1,204.4	$ 1,816.4	$ 1,814.7	$ 1,814.7