Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended		3 Months Ended	12 Months Ended
		Jan. 31, 2022		Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Common Share [Line Items]
Net income (loss) attributable to Targa Resources Corp.					$ 1,195.5	$ 71.2	$ (1,553.9)
Less: Premium on repurchase of noncontrolling interests, net of tax	[1]				53.2
Less: Deemed dividends on Series A Preferred					215.5		39.2
Net income (loss) attributable to common shareholders		$ (896.8)			$ 896.8	$ (16.1)	$ (1,684.8)
Weighted average shares outstanding - basic (in shares)					227.3	228.6	232.2
Dilutive effect of unvested stock awards	[2]				3.8
Weighted average shares outstanding - diluted (in shares)					231.1	228.6	232.2
Net income (loss) per common share - basic					$ 3.95	$ (0.07)	$ (7.26)
Net income (loss) per common share - diluted					$ 3.88	$ (0.07)	$ (7.26)
Series A Preferred Stock [Member]
Earnings Per Common Share [Line Items]
Less: Dividends on Series A Preferred	[3]	30.0				$ 87.3	$ 91.7
Less: Deemed dividends on Series A Preferred		$ 215.5	[4]	$ 215.5			$ 39.2	[4]

[1] Represents premium paid on the DevCo JV Repurchase. See Note 4 – Acquisitions and Divestitures.

[2] For the years ended December 31, 2021 and 2020, all unvested restricted stock awards and Series A Preferred were antidilutive because a net loss existed for each of those periods.

[3] Includes $8.2 million and $1.1 million attributable to the dividends paid upon the full redemption and partial repurchase of Series A Preferred in 2022 and 2020, respectively.

[4] Includes $215.5 million and $1.6 million attributable to the full redemption and partial repurchase of Series A Preferred in 2022 and 2020, respectively. See Note 11 – Preferred Stock for further discussion.