Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest Income (Expense), Net [Abstract]
Interest expense	$ 284	$ 171	$ 572	$ 309
Interest income	(4)	(5)	(9)	(9)
Interest expense, net	$ 280	$ 166	$ 563	$ 300