Debt Obligations - Summary Of Debt Obligations (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Current Obligations of the Partnership [Abstract]
Current debt	[1]	$ 275.0	$ 219.3
Long-term [Abstract]
Long-term debt		4,606.0	5,718.8
Long-term debt including Unamortized premium(discount) and Debt issuance costs	[1]	4,640.1	5,761.5
Debt issuance costs, net of amortization	[1]	(34.1)	(42.7)
Total debt obligations	[1]	4,881.0	5,938.1
Letters of credit outstanding		13.2	12.9
Secured Debt [Member] | TRC Senior Secured Term Loan due February 2022 [Member]
Long-term [Abstract]
Long-term debt		160.0	160.0
Unamortized discount/premium		(2.2)	(2.5)
Senior Unsecured Notes [Member] | Targa Pipeline Partners LP [Member] | Senior Unsecured 6 5/8% Notes due October 2020 [Member]
Long-term [Abstract]
Long-term debt	[2]	0.0	12.9
Unamortized discount/premium	[1]	0.0	0.2
Senior Unsecured Notes [Member] | Targa Pipeline Partners LP [Member] | Senior Unsecured 4 3/4% Notes due November 2021 [Member]
Long-term [Abstract]
Long-term debt	[2]	6.5	6.5
Senior Unsecured Notes [Member] | Targa Pipeline Partners LP [Member] | Senior Unsecured 5 7/8% Notes due August 2023 [Member]
Long-term [Abstract]
Long-term debt	[2]	48.1	48.1
Unamortized discount/premium	[1]	0.5	0.5
Revolving Credit Facility [Member] | TRC Senior Secured Revolving Credit Facility due February 2020 [Member]
Long-term [Abstract]
Long-term debt	[3]	275.0	440.0
Targa Resources Partners LP [Member] | TRP Senior Secured Revolving Credit Facility due October 2020 [Member]
Long-term [Abstract]
Long-term debt	[4]	150.0	280.0
Targa Resources Partners LP [Member] | Secured Debt [Member] | TRC Senior Secured Revolving Credit Facility [Member]
Long-term [Abstract]
Letters of credit outstanding	[3]	0.0	0.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 5% Notes due January 2018 [Member]
Long-term [Abstract]
Long-term debt	[1]	250.5	1,100.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 4 1/8% notes due November 2019 [Member]
Long-term [Abstract]
Long-term debt	[1]	749.4	800.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 6 5/8% Notes due October 2020 [Member]
Long-term [Abstract]
Long-term debt	[1]	0.0	342.1
Unamortized discount/premium	[1]	0.0	5.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 6 7/8% Notes due February 2021 [Member]
Long-term [Abstract]
Long-term debt	[1]	0.0	483.6
Unamortized discount/premium	[1]	0.0	(22.1)
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 6 3/8% Notes due August 2022 [Member]
Long-term [Abstract]
Long-term debt	[1]	278.7	300.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 5 1/4% Notes due May 2023 [Member]
Long-term [Abstract]
Long-term debt	[1]	559.6	583.7
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 4 1/4% Notes due November 2023 [Member]
Long-term [Abstract]
Long-term debt	[1]	583.9	623.5
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 6 3/4% Notes due March 2024 [Member]
Long-term [Abstract]
Long-term debt	[1]	580.1	600.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 5 1/8% Notes due February 2025 [Member]
Long-term [Abstract]
Long-term debt	[1]	500.0	0.0
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 5 3/8% Notes due February 2027 [Member]
Long-term [Abstract]
Long-term debt	[1]	500.0	0.0
Targa Resources Partners LP [Member] | Revolving Credit Facility [Member] | TRP Senior Secured Revolving Credit Facility due October 2020 [Member]
Long-term [Abstract]
Letters of credit outstanding	[3]	$ 13.2	$ 12.9

[1] While we consolidate the debt of the Partnership in our financial statements, we do not have the obligation to make interest payments or debt payments with respect to the debt of the Partnership.

[2] TPL notes are not guaranteed by us or the Partnership.

[3] As of December 31, 2016, availability under TRC’s $670 million senior secured revolving credit facility (“TRC Revolver”) was $395.0 million.

[4] As of December 31, 2016, availability under the Partnership’s $1.6 billion senior secured revolving credit facility (“TRP Revolver”) was $1,436.8 million.