(Deficit) Equity - Schedule of Number of Units Outstanding (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
General Partner SPLC
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	4,761,012	4,567,588
June 2019 Acquisition (in units)		193,424
Unit distribution (in units)	(4,761,012)
Ending balance (in units)	0	4,761,012
Preferred Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	0	0
June 2019 Acquisition (in units)		0
Unit distribution (in units)	50,782,904
Ending balance (in units)	50,782,904	0
General Public | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	123,832,233	123,832,233
June 2019 Acquisition (in units)		0
Unit distribution (in units)	0
Ending balance (in units)	123,832,233	123,832,233
Shell Pipeline Company L P | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	109,457,304	99,979,548
June 2019 Acquisition (in units)		9,477,756
Unit distribution (in units)	160,000,000
Ending balance (in units)	269,457,304	109,457,304