Equity, Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended				12 Months Ended
	Aug. 14, 2017	Aug. 04, 2017	Jul. 19, 2017	Jun. 30, 2017	[1],[2]	Mar. 31, 2017		Dec. 31, 2016
Distribution Made to Member or Limited Partner
Quarterly Distribution Per Unit				$ 0.971		$ 0.94	[1]	$ 0.91
Total Cash Distribution including general partner IDRs (in millions)				$ 147		$ 140	[1]	$ 140
Date of Distribution						May 15, 2017		Feb. 14, 2017
Unitholders Record Date						May 05, 2017		Feb. 03, 2017
Subsequent Event
Distribution Made to Member or Limited Partner
Date of Distribution	Aug. 14, 2017
Unitholders Record Date		Aug. 04, 2017
Distribution Made to Limited Partner, Declaration Date			Jul. 19, 2017

[1] This distribution is net of $12.5 million of IDRs waived by TLGP for each of the three months ended June 30, 2017 and March 31, 2017.

[2] This distribution was declared on July 19, 2017 and will be paid on the date of distribution.