Taxes on Income - Current and Deferred (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended		3 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Mar. 25, 2012
Successor
Income Tax Disclosure
Federal	$ (43)	$ 261	$ (52)
State	3	24	(7)
Current Income Tax Expense (Benefit)	(40)	285	(59)
Federal	81	(114)	119
State	(2)	(25)	38
Deferred income taxes	79	(139)	157
Total income tax expense	39	146	98
Predecessor
Income Tax Disclosure
Federal				0
State				(1)
Current Income Tax Expense (Benefit)				(1)
Federal				10
State				3
Deferred income taxes				13
Total income tax expense				$ 12