CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY - 6 months ended Jun. 30, 2017 - USD ($) shares in Millions, $ in Millions		Limited Partners Common Units	Limited Partners Class B Units	General Partner	Accumulated Other Comprehensive Loss	[1]	Non-Controlling Interest		Equity of former parent of PNGTS		Total
Partners' Equity at beginning of year at Dec. 31, 2016		$ 1,002	$ 117	$ 27	$ (2)	[2]	$ 97	[2]	$ 31	[2]	$ 1,272	[2],[3]
Partners' Equity at beginning of year (in units) at Dec. 31, 2016		67.4	1.9
Increase (Decrease) in Partners' Equity
Net income	[2]	$ 122		8			6		2		138
Other comprehensive income	[2]				1						1
ATM equity issuance, net (Note 7)		$ 90		2							92	[2]
ATM equity issuance, net (Note 7) (in units)		1.6
Reclassification of common units no longer subject to rescission (Note 7 )		$ 81		2							83	[2]
Acquisition of interest in PNGTS and Iroquois (Note 6)		(371)		(8)					(32)	[2]	(411)	[2]
Distributions	[2]	(129)	$ (22)	(6)			(2)		$ (1)		(160)
Partners' Equity at end of year at Jun. 30, 2017		$ 795	$ 95	$ 25	$ (1)	[2]	$ 101	[2]			$ 1,015	[2]
Partners' Equity at end of year (in units) at Jun. 30, 2017		69.0	1.9

[1] Losses related to cash flow hedges reported in Accumulated Other Comprehensive Loss and expected to be reclassified to Net Income in the next 12 months are estimated to be $2 million. These estimates assume constant interest rates over time; however, the amounts reclassified will vary based on actual value of interest rates at the date of settlement.Recast to consolidate PNGTS for all periods presented. See Notes 2 and 6.

[2] Recast to consolidate PNGTS for all periods presented. See Notes 2 and 6.

[3] Recast to consolidate PNGTS for all periods presented (Refer to Notes 2 and 6).