UNAUDITED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Sep. 30, 2019	Dec. 31, 2018
Common unitholders' capital account, units outstanding (in shares)	233,289,537
Shell Pipeline Company L P
General partners' capital account, units issued (in shares)	4,761,012	4,567,588
General partners' capital account, units outstanding (in shares)	4,761,012	4,567,588
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	99,979,548
Common unitholders' capital account, units outstanding (in shares)	109,457,304	99,979,548