(Deficit) Equity - Units Outstanding (Details)		3 Months Ended
	Apr. 01, 2020 $ / shares shares	Mar. 31, 2021 shares	Dec. 31, 2020 shares
Class of Stock [Line Items]
Common unitholders' capital account, units outstanding (in shares)		393,289,537	393,289,537
Percent of consideration payable in cash	90.00%
Common Units
Class of Stock [Line Items]
Common unitholders' capital account, units outstanding (in shares)		123,832,233	123,832,233
Limited Partner | Partnership Interests Restructuring Agreement | Series A Perpetual Convertible Preferred Units
Class of Stock [Line Items]
Preferred units, issued (in shares)	50,782,904
Unit distribution (in dollars per unit) | $ / shares	$ 23.63
Preferred Partner
Class of Stock [Line Items]
Capital units, publicly owned (in shares)		50,782,904	50,782,904
Preferred Partner | Series A Perpetual Convertible Preferred Units
Class of Stock [Line Items]
Conversion ratio	1
General Public | Common Units
Class of Stock [Line Items]
Capital units, publicly owned (in shares)		123,832,233
Shell Pipeline Company L P
Class of Stock [Line Items]
Preferred units, issued (in shares)		50,782,904	50,782,904
Shell Pipeline Company L P | Series A Perpetual Convertible Preferred Units
Class of Stock [Line Items]
Conversion ratio	1
Closing price per share, threshold (in dollars per share) | $ / shares	$ 33.082
Closing price per share, percent of issuance price, threshold	140.00%
Closing price per share, number of trading days threshold	20 days
Closing price per share, number of trading days preceding notice of conversion	30 days
Shell Pipeline Company L P | Common Units
Class of Stock [Line Items]
Common unitholders' capital account, units outstanding (in shares)		269,457,304	269,457,304
Capital units, publicly owned (in shares)		269,457,304
Shell Pipeline Company L P | Limited Partner | Limited Partner Interest
Class of Stock [Line Items]
Ownership interest percentage		68.50%