Debt Obligations - Summary Of Debt Obligations (Details) - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021
Current:
Partnership accounts receivable securitization facility, due April 2022	[1]	$ 270.0	$ 150.0
Finance lease liabilities		13.8	12.8
Current debt obligations		283.8	162.8
Long-term [Abstract]
Long-term debt including Unamortized premium(discount) and Debt issuance costs		6,992.6	6,465.7
Debt issuance costs, net of amortization		(41.3)	(45.0)
Finance lease liabilities		13.6	13.7
Long-term debt	[2]	6,964.9	6,434.4
Total debt obligations		7,248.7	6,597.2
Letters of credit outstanding		58.7	71.3
Senior Unsecured Notes [Member] | Senior Unsecured 5.875% Notes due April 2026 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3],[4]	963.2	963.2
Senior Unsecured Notes [Member] | Senior Unsecured 5.375% Notes due February 2027 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3],[5]	0.0	468.1
Senior Unsecured Notes [Member] | Senior Unsecured 6.500% Notes due July 2027 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3]	705.2	705.2
Senior Unsecured Notes [Member] | Senior Unsecured 5.000% Notes due January 2028 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3]	700.3	700.3
Senior Unsecured Notes [Member] | Senior Unsecured 6.875% Senior Notes due January 2029 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3]	679.3	679.3
Senior Unsecured Notes [Member] | Senior Unsecured 5.500% Notes due March 2030 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3]	949.6	949.6
Senior Unsecured Notes [Member] | Senior Unsecured of 4.875% Senior Notes due February 2031 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3]	1,000.0	1,000.0
Senior Unsecured Notes [Member] | Senior Unsecured of 4.000% Senior Notes due January 2032 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[3]	1,000.0	1,000.0
Revolving Credit Facility [Member] | TRGP Senior Revolving Credit Facility due February 2027 [Member]
Long-term [Abstract]
Long-term debt	[6]	995.0	0.0
Revolving Credit Facility [Member] | TRGP Senior Revolving Credit Facility due February 2027 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Letters of credit outstanding		58.7	0.0
Revolving Credit Facility [Member] | TRP Senior Revolving Credit Facility due June 2023 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Letters of credit outstanding	[3]	$ 0.0	$ 71.3

[1] As of March 31, 2022, the Partnership had $270.0 million of qualifying receivables under its $400.0 million accounts receivable securitization facility (“Securitization Facility”), resulting in $130.0 million of availability.

[2] In April 2022, we, along with certain of our subsidiaries as guarantors thereto, completed an underwritten public offering of (i) $750.0 million aggregate principal amount of our 4.200% Senior Notes due 2033 (the “4.200% Notes”) and (ii) $750.0 million aggregate principal amount of our 4.950% Senior Notes due 2052 (the “4.950% Notes”), resulting in net proceeds of approximately $1.5 billion.

[3] As of February 2022, we guarantee all of the Partnership’s outstanding senior unsecured notes.

[4] In April 2022, the Partnership purchased $484.3 million aggregate principal amount of its outstanding 5.875% Senior Notes due 2026 (the “5.875% Notes”) pursuant to an offer to purchase for cash (the “Tender Offer”) any and all outstanding 5.875% Notes. Concurrent with the launch of the Tender Offer, the Partnership exercised its right to redeem any of the 5.875% Notes not validly tendered and purchased in the Tender Offer, and such 5.875% Notes were redeemed in April 2022.

[5] In March 2022, the Partnership redeemed all of the outstanding 5.375% Senior Notes due 2027 (the “5.375% Notes”) with the available liquidity under the TRGP Revolver.

[6] In February 2022, we entered into a new $2.75 billion TRGP senior revolving credit facility, (the “TRGP Revolver”) which matures in February 2027. In connection with our entry into the TRGP Revolver, we terminated our previous TRGP senior secured revolving credit facility (the “Previous TRGP Revolver”) and the Partnership’s senior secured revolving credit facility (the “Partnership Revolver”). As of March 31, 2022, availability under the TRGP Revolver was $1.7 billion. As of December 31, 2021, we had no balance outstanding under the Previous TRGP Revolver or the Partnership Revolver.