CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY - USD ($) shares in Millions, $ in Millions	Limited Partners Common units GTN	Limited Partners Common units Bison	Limited Partners Common units GTN and Bison	Limited Partners Common units Equity Issuance, May 2013	Limited Partners Common units ATM Equity Issuance Program	Limited Partners Common units	Limited Partners Class B units Unit issuances	Limited Partners Class B units	General Partner GTN	General Partner GTN and Bison	General Partner Equity Issuance, May 2013	General Partner ATM Equity Issuance Program	General Partner	Accumulated Other Comprehensive Loss	[1]	Non-controlling interests GTN	Non-controlling interests Bison	Non-controlling interests	Equity of former parent	[2]	GTN	Bison	GTN and Bison	Equity Issuance, May 2013	ATM Equity Issuance Program	Unit issuances	Total
Partners' Equity at beginning of year at Dec. 31, 2012						$ 1,275							$ 27	$ (1)				$ 448	$ 673								$ 2,422
Partners' Equity at beginning of year (in units) at Dec. 31, 2012						53.5
Increase (Decrease) in Partners' Equity
Net income (loss)						$ 152							3					36									191	[2]
Net income attributed to former parent of GTN and Bison						(26)													26
Distributions to former parent of GTN and Bison																			(37)								(37)
Equity Issuance, net (Note 9); Issuance of Units (Note 6 and 9)				$ 373							$ 8													$ 381
Equity Issuance, net (Note 9); Issuance of Units (Note 6 and 9) (in units)				8.8
Acquisition of the remaining interest in GTN, 2015; Bison 2014; Excess purchase price paid over net acquired assets, 2013 (Note 6)			$ (268)							$ (6)													$ (274)
Distributions						(184)							(4)					(52)									(240)
Equity contribution from Bison's former parent (Note 16)																		8	10								18
Former parent carrying amount of acquired entities																			$ (672)								(672)
Adjustment to the 2011 Acquisition						1																					1
Other						(1)																					(1)
Partners' Equity at end of year at Dec. 31, 2013						$ 1,322							28	(1)				440									1,789
Partners' Equity at end of year (in units) at Dec. 31, 2013						62.3
Increase (Decrease) in Partners' Equity
Net income (loss)						$ 168							4					32									204
Other Comprehensive Loss														(1)													(1)
Equity Issuance, net (Note 9); Issuance of Units (Note 6 and 9)					$ 71							$ 2													$ 73
Equity Issuance, net (Note 9); Issuance of Units (Note 6 and 9) (in units)					1.3
Acquisition of the remaining interest in GTN, 2015; Bison 2014; Excess purchase price paid over net acquired assets, 2013 (Note 6)		$ (29)															$ (188)					$ (217)
Distributions						(207)							(5)					(50)									(262)
Partners' Equity at end of year at Dec. 31, 2014						$ 1,325							29	(2)				234									1,586
Partners' Equity at end of year (in units) at Dec. 31, 2014						63.6
Increase (Decrease) in Partners' Equity
Net income (loss)						$ (2)		$ 12					3					7									20
Equity Issuance, net (Note 9); Issuance of Units (Note 6 and 9)					$ 43		$ 95					$ 1													$ 44	$ 95
Equity Issuance, net (Note 9); Issuance of Units (Note 6 and 9) (in units)					0.7		1.9
Acquisition of the remaining interest in GTN, 2015; Bison 2014; Excess purchase price paid over net acquired assets, 2013 (Note 6)	$ (124)								$ (3)							$ (232)					$ (359)
Equity Contribution (Note 6)													2														2
Distributions						(221)							(7)					$ (9)									(237)
Partners' Equity at end of year at Dec. 31, 2015						$ 1,021		$ 107					$ 25	$ (2)													$ 1,151
Partners' Equity at end of year (in units) at Dec. 31, 2015						64.3		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 $1 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.

[2] Recast as discussed in Note 2 and Note 6.