Quarterly Financial Data - Unaudited (Details) (Successor [Member], USD $) In Millions, unless otherwise specified	3 Months Ended								11 Months Ended	12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011
Successor [Member]
schedule of quarterly financial information Unaudited [Line Items]
Revenue, Net	$ 5,428	$ 5,343	$ 5,062	$ 5,002	$ 5,264	$ 4,961	$ 4,790	$ 4,533	$ 15,059	$ 20,835	$ 19,548
Operating Income (Loss)	1,640	1,669	1,438	1,265	1,617	1,380	1,209	1,104	4,053	6,012	5,310
Net income	$ 932	$ 937	$ 802	$ 701	$ 909	$ 766	$ 690	$ 607	$ 2,235	$ 3,372	$ 2,972