Debt Obligations - Summary Of Debt Obligations (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Current:
Partnership accounts receivable securitization facility, due September 2023	[1]	$ 704.0	$ 800.0
Finance lease liabilities		35.0	34.3
Current debt obligations		739.0	834.3
Long-term [Abstract]
Long-term debt including Unamortized premium(discount) and Debt issuance costs		11,298.4	10,574.7
Debt issuance costs, net of amortization		(67.7)	(65.6)
Finance lease liabilities		208.9	193.0
Long-term debt		11,439.6	10,702.1
Total debt obligations		12,178.6	11,536.4
Letters of credit outstanding		33.2	33.2
Senior Unsecured Notes [Member]
Long-term [Abstract]
Unamortized discount		(41.0)	(8.4)
Senior Unsecured Notes [Member] | Senior Unsecured 5.200% fixed rate, due July 2027 [Member]
Long-term [Abstract]
Long-term debt		750.0	750.0
Senior Unsecured Notes [Member] | Senior Unsecured 5.200% fixed rate, due July 2027 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[2]	705.2	705.2
Senior Unsecured Notes [Member] | Senior Unsecured 4.200% Notes due February 2033 [Member]
Long-term [Abstract]
Long-term debt		750.0	750.0
Senior Unsecured Notes [Member] | Senior Unsecured 6.125% Fixed Rate, Due March 2033 [Member]
Long-term [Abstract]
Long-term debt	[3]	900.0	0.0
Senior Unsecured Notes [Member] | Senior Unsecured 4.950% Notes due April 2052 [Member]
Long-term [Abstract]
Long-term debt		750.0	750.0
Senior Unsecured Notes [Member] | Senior Unsecured 6.250% fixed rate, due July 2052 [Member]
Long-term [Abstract]
Long-term debt		500.0	500.0
Senior Unsecured Notes [Member] | Senior Unsecured 6.500% Fixed Rate, Due February 2053 [Member]
Long-term [Abstract]
Long-term debt	[3]	850.0	0.0
Senior Unsecured Notes [Member] | Senior Unsecured 5.000% Notes due January 2028 [Member] | Targa Resources Partners LP [Member]
Long-term [Abstract]
Long-term debt	[2]	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	[2]	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	[2]	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	[2]	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	[2]	1,000.0	1,000.0
Term Loan Facility, Variable Rate, due July 2025
Long-term [Abstract]
Long-term debt		1,500.0	1,500.0
Revolving Credit Facility [Member] | TRGP Senior Revolving Credit Facility due February 2027 [Member]
Long-term [Abstract]
Long-term debt	[4]	305.0	1,298.7
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	[4]	$ 33.2	$ 33.2

[1] The Partnership's accounts receivable securitization facility (the “Securitization Facility”) provides up to $800 million of borrowing capacity. As of March 31, 2023, the Partnership had $704.0 million of qualifying receivables.

[2] We guarantee all of the Partnership’s outstanding senior unsecured notes.

[3] In January 2023, we completed an underwritten public offering of (i) $900.0 million aggregate principal amount of our 6.125% Senior Notes due 2033 (the “6.125% Notes”) and (ii) $850.0 million aggregate principal amount of our 6.500% Senior Notes due 2053 (the “6.500% Notes”), resulting in net proceeds of approximately $1.7 billion.

[4] We maintain an unsecured commercial paper note program (the “Commercial Paper Program”), the borrowings of which are supported through maintaining a minimum available borrowing capacity under our $2.75 billion TRGP senior revolving credit facility (the “TRGP Revolver”) equal to the aggregate amount outstanding under the Commercial Paper Program. As of March 31, 2023, the TRGP Revolver had no borrowings outstanding and the Commercial Paper Program had $305.0 million borrowings outstanding, resulting in approximately $2.4 billion of available liquidity, after accounting for outstanding letters of credit.