Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2012	$ 72	$ 115
Balance at March 31, 2013	72	115
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2012	293	336
Reclassification from accumulated other comprehensive income	(43)
Balance at March 31, 2013	293	336
Postretirement Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2012	(219)	(222)
Reclassification from accumulated other comprehensive income	(1)
Balance at March 31, 2013	(219)	(222)
Unrealized loss on foreign exchange agreements
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from accumulated other comprehensive income	(2)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2012	(2)	1
Reclassification from accumulated other comprehensive income	(1)
Balance at March 31, 2013	(2)	1
Cost of revenue | Postretirement Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from accumulated other comprehensive income	1
Selling, general and administrative expenses | Postretirement Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from accumulated other comprehensive income	2
Other non-operating expense, net | Postretirement Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from accumulated other comprehensive income	$ 1