CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net income (loss)	$ 32.1	$ (11.2)	$ 56.3	$ 148.6
Commodity hedging contracts:
Other comprehensive income (loss), pre-tax	76.7	(115.7)	61.7	(119.7)
Other comprehensive income (loss), related income tax	(18.8)	27.8	(15.1)	28.9
Other comprehensive income (loss), after tax	57.9	(87.9)	46.6	(90.8)
Comprehensive income (loss)	90.0	(99.1)	102.9	57.8
Less: Comprehensive income (loss) attributable to noncontrolling interests	79.4	12.5	152.7	40.4
Comprehensive income (loss) attributable to Targa Resources Corp.	10.6	(111.6)	(49.8)	17.4
Commodity Contracts [Member]
Commodity hedging contracts:
Change in fair value, pre-tax	118.2	(139.6)	167.8	(178.0)
Change in fair value, related income tax	(28.8)	32.3	(40.7)	43.0
Change in fair value, after tax	89.4	(107.3)	127.1	(135.0)
Settlements reclassified to revenues, pre-tax	(41.5)	23.9	(106.1)	58.3
Settlements reclassified to revenues, related income tax	10.0	(4.5)	25.6	(14.1)
Settlements reclassified to revenues, after tax	$ (31.5)	$ 19.4	$ (80.5)	$ 44.2