Debt Obligations - Interest Rates on Variable-Rate Debt Obligations (Details)	Jun. 30, 2020
Targa Resources Partners LP [Member] | Securitization Facility [Member]
Range of interest rates and weighted average interest rate [Abstract]
Weighted average interest rate incurred	2.10%
Minimum [Member] | Targa Resources Partners LP [Member] | Securitization Facility [Member]
Range of interest rates and weighted average interest rate [Abstract]
Range of interest rates incurred	1.50%
Maximum [Member] | Targa Resources Partners LP [Member] | Securitization Facility [Member]
Range of interest rates and weighted average interest rate [Abstract]
Range of interest rates incurred	2.70%
TRP Revolver [Member]
Range of interest rates and weighted average interest rate [Abstract]
Weighted average interest rate incurred	2.50%
TRP Revolver [Member] | Minimum [Member]
Range of interest rates and weighted average interest rate [Abstract]
Range of interest rates incurred	1.90%
TRP Revolver [Member] | Maximum [Member]
Range of interest rates and weighted average interest rate [Abstract]
Range of interest rates incurred	6.00%