Employee Benefit Plans - Change in Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 0	$ 0	$ 0
Defined Benefit Plan, Fair Value of Plan Assets	1,726	1,884	2,683
Defined Benefit Plan, Actual Return on Plan Assets	(48)	326
Company contributions	0	18
Defined Benefit Plan, Benefits Paid	110	1,143
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	0	0
Plan participant contributions	0	0
Defined Benefit Plan, Cost of Providing Special or Contractual Termination Benefits Recognized During Period	0	0	26
Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	(427)	1	0
Defined Benefit Plan, Fair Value of Plan Assets	1,009	2,325	2,373
Defined Benefit Plan, Actual Return on Plan Assets	38	433
Company contributions	33	69
Defined Benefit Plan, Benefits Paid	1,364	393
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	(25)	(160)
Plan participant contributions	2	3
Defined Benefit Plan, Cost of Providing Special or Contractual Termination Benefits Recognized During Period	0	0	0
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	(427)	1	0
Defined Benefit Plan, Fair Value of Plan Assets	2,735	4,209	5,056
Defined Benefit Plan, Actual Return on Plan Assets	(10)	759
Company contributions	33	87
Defined Benefit Plan, Benefits Paid	1,474	1,536
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	(25)	(160)
Plan participant contributions	2	3
Defined Benefit Plan, Cost of Providing Special or Contractual Termination Benefits Recognized During Period	$ 0	$ 0	$ 26