Partners' Capital and Distributions - Noncontrolling Interests in Subsidiaries (Details) - SLC Pipeline LLC	3 Months Ended
Dec. 31, 2017
Partners Capital and Distributions
Noncontrolling interests in subsidiaries	75.00%
Ownership percentage sold	25.00%

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant