UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Sep. 30, 2017	Dec. 31, 2016
Limited partners' capital account, units outstanding (in shares)	187,782,369
Shell Pipeline Company L P
General partners' capital account, units issued (in shares)	3,832,293	3,618,723
General partners' capital account, units outstanding (in shares)	3,832,293	3,618,723
Common Units | General Public
Limited partners' capital account, units issued (in shares)	98,832,233	88,367,308
Limited partners' capital account, units outstanding (in shares)	98,832,233	88,367,308
Common Units | Shell Pipeline Company L P
Limited partners' capital account, units issued (in shares)	88,950,136	21,475,068
Limited partners' capital account, units outstanding (in shares)	88,950,136	21,475,068
Subordinated Units | Shell Pipeline Company L P
Limited partners' capital account, units issued (in shares)	0	67,475,068
Limited partners' capital account, units outstanding (in shares)	0	67,475,068