Business and Basis of Presentation - Reclassifications (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Reclassifications [Line Items]
Selling	$ 113	$ 68	$ 273	$ 213
Cost of service	130	89	338	272
General & administrative	54	31	154	94
Total		188		579
As Previously Reported
Schedule of Reclassifications [Line Items]
Selling		85		270
Cost of service		70		215
General & administrative		33		94
Total		188		579
Reclassifications
Schedule of Reclassifications [Line Items]
Selling		(17)		(57)
Cost of service		19		57
General & administrative		(2)		0
Total		$ 0		$ 0