CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) [Abstract]
Net income attributable to Targa Resources Corp.	$ 19.6	$ 13.4
Commodity hedging contracts:
Change in fair value, pre-tax	(1.5)	(1.2)
Change in fair value, related income tax	0.6	0.5
Change in fair value, after tax	(0.9)	(0.7)
Settlement reclassified to revenues, pre-tax	0.8	(0.9)
Settlement reclassified to revenues, related income tax	(0.3)	0.4
Settlement reclassified to revenues, after tax	0.5	(0.5)
Interest rate swaps:
Settlements reclassified to interest expense, net, pre-tax	0.2	0.2
Settlements reclassified to interest expense, net, related income tax	(0.1)	(0.1)
Settlements reclassified to interest expense, net, after tax	0.1	0.1
Other comprehensive income (loss) attributable to Targa Resources Corp., pre-tax	(0.5)	(1.9)
Other comprehensive income (loss) attributable to Targa Resources Corp., related income tax	0.2	0.8
Other comprehensive income (loss) attributable to Targa Resources Corp., after tax	(0.3)	(1.1)
Comprehensive income attributable to Targa Resources Corp.	19.3	12.3
Net income attributable to noncontrolling interests	87.3	20.4
Commodity hedging contracts:
Change in fair value, pre-tax	(10.3)	(6.4)
Change in fair value, related income tax	0	0
Change in fair value, after tax	(10.3)	(6.4)
Settlement reclassified to revenues, pre-tax	5.5	(5.7)
Settlement reclassified to revenues, related income tax	0	0
Settlement reclassified to revenues, after tax	5.5	(5.7)
Interest rate swaps:
Settlements reclassified to interest expense, net, pre-tax	1.1	1.5
Settlements reclassified to interest expense, net, related income tax	0	0
Settlements reclassified to interest expense, net, after tax	1.1	1.5
Other comprehensive income (loss) attributable to noncontrolling interests, before tax	(3.7)	(10.6)
Other comprehensive income (loss) attributable to noncontrolling interests, related income tax	0	0
Other comprehensive income (loss) attributable to noncontrolling interests, after tax	(3.7)	(10.6)
Comprehensive income attributable to noncontrolling interests	83.6	9.8
Total comprehensive income	$ 102.9	$ 22.1