Interest and other income/(expense), net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Nonoperating Income (Expense) [Abstract]
Interest expense	$ (10)	$ (23)	$ (23)
Interest income	176	52	27
Foreign currency exchange losses, net	(76)	(66)	(87)
Other	1	6	(1)
Interest and other income/(expense), net	$ 91	$ (31)	$ (84)