CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Jul. 10, 2013	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2013
Successor [Member]
Net loss	$ (151)	$ (9)		$ (1,995)	$ (3,345)	$ (1,860)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment	1	0		(11)	(25)	3
Unrealized holding (losses) gains on securities:
Unrealized holding (losses) gains on securities	1	0		(1)	(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		(1)	(6)	6
Unrecognized net periodic pension and other postretirement benefits:
Net actuarial (loss) gain	(147)	0		(38)	(393)	93
Net prior service credits arising during the period	0	0		9	0	0
Less: Amortization of actuarial loss, included in net loss	0	0		10	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		(19)	(334)	93
Other comprehensive (loss) income	(145)	0		(31)	(365)	102
Comprehensive (loss)	$ (296)	(9)		$ (2,026)	$ (3,710)	$ (1,758)
Predecessor [Member]
Net loss		(643)	$ (1,158)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment		(2)	(8)
Unrealized holding (losses) gains on securities:
Unrealized holding (losses) gains on securities		1	(4)
Less: Reclassification adjustment for realized gains included in net loss		0	0
Net unrealized holding (losses) gains on securities		1	(4)
Unrecognized net periodic pension and other postretirement benefits:
Net actuarial (loss) gain		0	0
Net prior service credits arising during the period		0	0
Less: Amortization of actuarial loss, included in net loss		15	35
Less: Settlement event charge, included in net loss		0	0
Net unrecognized net periodic pension and other postretirement benefits		15	35
Other comprehensive (loss) income		14	23
Comprehensive (loss)		$ (629)	$ (1,135)