Employee Benefit Plan - Fair Value of Pension Plan Assets Based on Level 3 Unobservable Inputs (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the year	$ 104	$ 105
Purchases/sales, net	(56)	10
Actual return on plan assets	(2)	4
Currency impact	(4)	(15)
Balance at end of the year	$ 42	$ 104