Derivative Financial Instruments (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI on derivative	$ 2	[1]	$ 0	[1]	$ 4	[1]	$ 0	[1]
Amount of gain (loss) reclassified from OCI into cost of revenue	0		0		(1)		0
Amount of gain (loss) recognized in net income on derivative	$ 0	[2]	$ 0	[2]	$ 0	[2]	$ 0	[2]

[1] Effective portion

[2] Ineffective portion and amount excluded from effectiveness testing