Debt Obligations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013
Schedule of Debt Instruments [Line Items]
Long-term debt	$ 2,891.7		$ 2,989.3
Letters of credit outstanding	97.2		86.8
Revolving Credit Facility [Member] | TRC Senior Secured Revolving Credit Facility due 2017 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	72.0	[1]	84.0	[1]
Maturity date	Oct. 31, 2017
Letters of credit outstanding	0	[1]	0	[1]
Maximum borrowing capacity	150.0
Remaining borrowing capacity	78.0
Range of interest rates and weighted average interest rate [Abstract]
Interest Rates Incurred (in hundredths)	2.90%
Weighted Average Interest Rate Incurred (in hundredths)	2.90%
Targa Resources Partners LP [Member] | Revolving Credit Facility [Member] | TRP Senior Secured Revolving Credit Facility due 2017 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	355.0	[2],[3]	395.0	[2],[3]
Maturity date	Oct. 31, 2017
Letters of credit outstanding	97.2	[3]	86.8	[3]
Maximum borrowing capacity	1,200.0
Remaining borrowing capacity	747.8
Range of interest rates and weighted average interest rate [Abstract]
Range of Interest Rates Incurred, Minimum (in hundredths)	2.20%
Range of Interest Rates Incurred, Maximum (in hundredths)	4.50%
Weighted Average Interest Rate Incurred (in hundredths)	2.30%
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 7 7/8% Notes due October 2018 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	250.0	[2]	250.0	[2]
Interest rate on fixed rate debt (in hundredths)	7.875%
Maturity date	Oct. 31, 2018
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 6 7/8% Notes due February 2021 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	483.6	[2]	483.6	[2]
Unamortized discount	(27.4)	[2]	(28.0)	[2]
Interest rate on fixed rate debt (in hundredths)	6.875%
Maturity date	Feb. 28, 2021
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 6 3/8% Notes due August 2022 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	300.0	[2]	300.0	[2]
Interest rate on fixed rate debt (in hundredths)	6.375%
Maturity date	Aug. 31, 2022
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 5 1/4% Notes due May 2023 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	600.0	[2]	600.0	[2]
Interest rate on fixed rate debt (in hundredths)	5.25%
Maturity date	May 31, 2023
Targa Resources Partners LP [Member] | Senior Unsecured Notes [Member] | Senior Unsecured 4 1/4% Notes due November 2023 [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	625.0	[2]	625.0	[2]
Interest rate on fixed rate debt (in hundredths)	4.25%
Maturity date	Nov. 30, 2023
Targa Resources Partners LP [Member] | Accounts receivable securitization facility [Member]
Schedule of Debt Instruments [Line Items]
Long-term debt	$ 233.5	[2],[4]	$ 279.7	[2],[4]
Maturity date	Dec. 31, 2014
Targa Resources Partners LP [Member] | Accounts receivable securitization facility [Member] | Partnership's Accounts Receivable Securitization Facility due 2014 [Member]
Range of interest rates and weighted average interest rate [Abstract]
Interest Rates Incurred (in hundredths)	0.90%
Weighted Average Interest Rate Incurred (in hundredths)	0.90%

[1] As of March 31, 2014, availability under TRC’s $150 million senior secured revolving credit facility was $78.0 million.

[2] 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.

[3] As of March 31, 2014, availability under the Partnership’s $1.2 billion senior secured revolving credit facility was $747.8 million.

[4] All amounts outstanding under the Partnership’s Securitization Facility are reflected as long-term debt in our balance sheet because the Partnership has the ability and intent to fund the Securitization Facility’s borrowings on a long-term basis.