Employee Benefit Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net service cost	$ 2	$ 3
Interest cost	30	36
Expected return on plan assets	(27)	(39)
Net benefit cost	5	0
U.S. Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net service cost	0	0
Interest cost	23	22
Expected return on plan assets	(18)	(18)
Net benefit cost	5	4
International Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net service cost	2	3
Interest cost	7	14
Expected return on plan assets	(9)	(21)
Net benefit cost	0	$ (4)
Defined Benefit Plan, Contributions by Employer	7
Defined Benefit Plan Estimated Total Employer Contributions in Current Fiscal Year	35
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	$ 28