Employee Benefit Plans, Net Cost (Details) (USD $) In Millions, unless otherwise specified	11 Months Ended	12 Months Ended		11 Months Ended	12 Months Ended		1 Months Ended
	Dec. 31, 2010 Successor [Member] Pension Benefits	Dec. 31, 2012 Successor [Member] Pension Benefits	Dec. 31, 2011 Successor [Member] Pension Benefits	Dec. 31, 2010 Successor [Member] Retiree Health and Welfare Benefits	Dec. 31, 2012 Successor [Member] Retiree Health and Welfare Benefits	Dec. 31, 2011 Successor [Member] Retiree Health and Welfare Benefits	Feb. 12, 2010 Predecessor [Member] Pension Benefits	Feb. 12, 2010 Predecessor [Member] Retiree Health and Welfare Benefits
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 28	$ 39	$ 32	$ 1	$ 1	$ 1	$ 3	$ 0
Interest cost	95	100	102	13	13	14	12	2
Expected return on plan assets	(108)	(118)	(120)				(14)
Amortization of net loss	0	10	0	0	1	0	4	0
Settlements	0	0	1				0
Net cost recognized	$ 15	$ 31	$ 15	$ 14	$ 15	$ 15	$ 5	$ 2