CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Trade receivables, allowances	$ 0.9	$ 0.1
Targa Resources Corp. stockholders' equity:
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	185,234,405	56,446,573
Common stock, shares outstanding (in shares)	184,720,525	56,020,266
Preferred stock, par value (in dollar per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	98,800,000	0
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury stock, shares (in shares)	513,880	426,307
Series A Preferred Stock [Member]
LIABILITIES, SERIES A PREFERRED STOCK AND OWNERS' EQUITY
Preferred Series A Liquidation Stock Percentage	9.50%
Preferred Stock, Liquidation Preference Per Share	$ 1,000
Preferred Stock, Shares Authorized	1,200,000
Preferred Stock, Shares Issued	1,200,000
Preferred Stock, Shares Outstanding	965,100