CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	[2]
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income		$ 263	[1]	$ 263	[2]	$ 58
Other comprehensive income
Change in fair value of cash flow hedges (Notes 11 and 19)		5		3	[2]
Reclassification to net income of gains and losses on cash flow hedges (Note 11)	[2]			(2)
Amortization of realized loss on derivative instrument (Notes 11 and 19)		1		1	[2]	1
Other comprehensive income on equity investments (Note 11)		1
Comprehensive income		270		265	[2]	59
Comprehensive income attributable to non-controlling interests		11		16	[2]	21
Comprehensive income attributable to controlling interests		$ 259		$ 249	[2]	$ 38

[1] Recast to consolidate PNGTS (Refer to Notes 2 and 7).

[2] Recast to consolidate PNGTS (Refer to Notes 2 and 7).