QUARTERLY OPERATIONS Quarterly Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended		3 Months Ended	9 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Mar. 25, 2012	Dec. 31, 2012
Operating revenues	$ 143	$ 132	$ 128	$ 178	$ 194	$ 182	$ 316	$ 393	$ 581	$ 1,085
Operating income	38	31	34	90	(619)	67	115	55	193	(382)
Net income (loss)	(7)	23	16	(35)	(669)	58	40	36	(3)	(535)
Net income (loss) attributable to partners	(7)	23	16	(41)	(647)	37	69	42	(9)	(499)
Predecessor
Operating revenues											443
Operating income											81
Net income (loss)											50
Net income (loss) attributable to partners											40
Successor
Operating revenues									581	1,085		1,263
Operating income									193	(382)		186
Net income (loss)									(3)	(535)		39
Net income (loss) attributable to partners									$ (9)	$ (499)		$ 88