Goodwill, Customer Relationships and Other Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended				6 Months Ended	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Customer relationships Y	Dec. 31, 2011 Customer relationships	Jun. 30, 2012 Capitalized software Y	Dec. 31, 2011 Capitalized software	Jun. 30, 2012 Tradename and patent	Dec. 31, 2011 Tradename and patent	Jun. 30, 2012 Other intangible assets Y	Mar. 31, 2011 Predecessor
Goodwill, Customer Relationships and Other Intangible Assets
Goodwill	$ 10,123		$ 10,123	$ 10,123
Goodwill, Customer Relationships and Other Intangible Assets
Customer relationships, net	6,300		6,300	6,788	6,300	6,788
Other intangible assets subject to amortization	1,422		1,422	1,587			1,329	1,460	93	127
Accumulated amortization amount					1,258	770	556	354	96	61
Other intangible assets subject to amortization
Estimated life (in years)					10						4
Estimated life, maximum (in years)							7
Amortization expense	$ 364	$ 399	$ 727									$ 58