Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Earnings Per Common Share [Line Items]
Net income (loss) attributable to Targa Resources Corp.		$ 497.0	$ 88.0
Less: Premium on repurchase of noncontrolling interests, net of tax	[1]	490.7	53.1
Net income (loss) attributable to common shareholders		$ 6.3	$ 13.1
Weighted average shares outstanding - basic		226.4	228.5
Dilutive effect of unvested stock awards		2.9	3.9
Weighted average shares outstanding - diluted (in shares)		229.3	232.4
Net income (loss) per common share - basic		$ 0.03	$ 0.06
Net income (loss) per common share - diluted		$ 0.03	$ 0.06
Series A Preferred Stock [Member]
Earnings Per Common Share [Line Items]
Less: Dividends on Series A Preferred Stock	[2]		$ 21.8

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

[2] The Series A Preferred had no mandatory redemption date, but was redeemable at our election for a 5% premium to the liquidation preference subsequent to March 16, 2022. In May 2022, we redeemed all of our issued and outstanding Series A Preferred.