Income Taxes Reconciliaton of Changes in Unrecognized Tax Benefits Liabilities / (Assets) (Details) (USD $) In Millions, unless otherwise specified	11 Months Ended	12 Months Ended		1 Months Ended
	Dec. 31, 2010 Successor [Member]	Dec. 31, 2012 Successor [Member]	Dec. 31, 2011 Successor [Member]	Feb. 12, 2010 Predecessor [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	$ 167	$ 110	$ 112	$ 166
Additions for tax positions related to current year	24	12	47	1
Reductions for tax positions taken in prior years	(58)	(2)	(40)	0
Additions for tax positions as a result of settlements			8	0
Reductions for tax positions as a result of settlements	(10)	(53)
Reductions for tax positions as a result of lapse of statute of limitations	(11)	(19)	(17)	0
Ending Balance	112	48	110	167
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		32
Unrecognized Tax Benefits	$ 112	$ 48	$ 110	$ 167