CONSOLIDATED STATEMENTS OF CHANGES IN OWNERS' EQUITY (Unaudited) - USD ($) $ in Millions	Total	Targa Badlands LLC [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Targa Badlands LLC [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member] Targa Badlands LLC [Member]
Balance at Dec. 31, 2023	$ 4,610.0		$ 0.2	$ 3,058.8		$ 492.0	$ 85.6	$ (896.9)	$ 1,870.3
Balance (in shares) at Dec. 31, 2023			222,611,000
Balance (in shares) at Dec. 31, 2023								17,484,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation on equity grants	14.6			14.6
Dividend equivalent rights	(0.7)					(0.7)
Shares issued under compensation program (in shares)			1,165,000
Shares tendered for tax withholding obligations	(36.5)							$ (36.5)
Shares tendered for tax withholding obligations (in shares)			(440,000)					440,000
Repurchases of common stock	$ (123.7)							$ (123.7)
Repurchases of common stock (in shares)	(1,186,444)		(1,186,000)					1,186,000
Excise tax on repurchases of common stock	$ (0.6)							$ (0.6)
Common stock dividends
Common stock dividends	(112.4)					(112.4)
Series A Preferred Stock dividends
Distributions to noncontrolling interests	(55.8)								(55.8)
Contributions from noncontrolling interests	1.8								1.8
Other comprehensive income (loss)	(51.7)						(51.7)
Net income (loss)	332.6					275.2			57.4
Balance at Mar. 31, 2024	4,577.6		$ 0.2	3,073.4		654.1	33.9	$ (1,057.7)	1,873.7
Balance (in shares) at Mar. 31, 2024			222,150,000
Balance (in shares) at Mar. 31, 2024								19,110,000
Balance at Dec. 31, 2024	$ 4,418.2		$ 0.2	3,089.1		1,190.0	27.5	$ (1,714.4)	1,825.8
Balance (in shares) at Dec. 31, 2024			217,764,000
Balance (in shares) at Dec. 31, 2024	24,000,284							24,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation on equity grants	$ 17.6			17.6
Dividend equivalent rights	(0.7)					(0.7)
Shares issued under compensation program (in shares)			564,000
Shares tendered for tax withholding obligations	(46.5)							$ (46.5)
Shares tendered for tax withholding obligations (in shares)			(216,000)					216,000
Repurchases of common stock	$ (124.9)							$ (124.9)
Repurchases of common stock (in shares)	(651,163)		(651,000)					651,000
Excise tax on repurchases of common stock	$ (0.5)							$ (0.5)
Common stock dividends
Common stock dividends	(164.5)					(164.5)
Series A Preferred Stock dividends
Distributions to noncontrolling interests	(4.7)								(4.7)
Repurchase of noncontrolling interests, net of tax		$ (1,779.7)			$ (70.5)					$ (1,709.2)
Other comprehensive income (loss)	(21.4)						(21.4)
Net income (loss)	279.8					270.5			9.3
Balance at Mar. 31, 2025	$ 2,572.7		$ 0.2	$ 3,036.2		$ 1,295.3	$ 6.1	$ (1,886.3)	$ 121.2
Balance (in shares) at Mar. 31, 2025			217,461,000
Balance (in shares) at Mar. 31, 2025	24,866,975							24,867,000