CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended		6 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2015	Dec. 31, 2013	Jul. 10, 2013	Dec. 31, 2012
Successor [Member]
Net loss	$ (151)	$ (9)	$ (27)	$ (3,345)	$ (1,860)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment	1	0	0	(25)	3
Unrealized holding (losses) gains on securities:
Unrealized holding (losses) gains on securities	1	0	0	(6)	6
Less: Reclassification adjustment for realized gains included in net loss	0	0	0	0	0
Net unrealized holding (losses) gains on securities	1	0	0	(6)	6
Unrecognized net periodic pension and other postretirement benefits:
Net actuarial (loss) gain	(147)	0	0	(393)	93
Less: Amortization of actuarial loss, included in net loss	0	0	0	0	0
Less: Settlement event charge, included in net loss	0	0	0	59	0
Net unrecognized net periodic pension and other postretirement benefits	(147)	0	0	(334)	93
Other comprehensive (loss) income	(145)	0	0	(365)	102
Comprehensive (loss)	(296)	(9)	(27)	(3,710)	(1,758)
Predecessor [Member]
Net loss		(643)				(1,158)	(4,326)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment		(2)				(8)	(4)
Unrealized holding (losses) gains on securities:
Unrealized holding (losses) gains on securities		1				(4)	5
Less: Reclassification adjustment for realized gains included in net loss		0				0	(3)
Net unrealized holding (losses) gains on securities		1				(4)	2
Unrecognized net periodic pension and other postretirement benefits:
Net actuarial (loss) gain		0				0	(404)
Less: Amortization of actuarial loss, included in net loss		15				35	65
Less: Settlement event charge, included in net loss		0				0	0
Net unrecognized net periodic pension and other postretirement benefits		15				35	(339)
Other comprehensive (loss) income		14				23	(341)
Comprehensive (loss)		$ (629)				$ (1,135)	$ (4,667)