UNAUDITED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Mar. 31, 2020	Dec. 31, 2019
Common unitholders' capital account, units outstanding (in shares)	233,289,537	233,289,537
Shell Pipeline Company L P
General partners' capital account, units issued (in shares)	4,761,012	4,761,012
General partners' capital account, units outstanding (in shares)	4,761,012	4,761,012
Common Units | General Public
Common unitholders' capital account, units issued (in shares)	123,832,233	123,832,233
Common unitholders' capital account, units outstanding (in shares)	123,832,233	123,832,233
Common Units | Shell Pipeline Company L P
Common unitholders' capital account, units issued (in shares)	109,457,304	109,457,304
Common unitholders' capital account, units outstanding (in shares)	109,457,304	109,457,304