Benefit Plans Benefit Plans (Weighted Average Assumptions) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
U.S. Defined Benefit Plans
Benefit Obligation:
Discount rates		4.44%	4.04%
Rates of compensation increase	[1]	3.34%	3.94%
Periodic Benefit Cost:
Discount rate		4.04%	4.89%
Expected long-term rate of return on plan assets		6.67%	6.92%
Rate of compensation increase	[1]	3.94%	3.94%
Defined benefit plan, benefit obligation subsidiary using salary bonds		$ 6	$ 748
Defined Benefit Plan Obligation subsidiary using compensation increase			$ 742
Foreign Defined Benefit Plans
Benefit Obligation:
Discount rates	[2]	11.37%	10.47%
Rates of compensation increase		6.32%	6.41%
Periodic Benefit Cost:
Discount rate		10.47%	10.80%
Expected long-term rate of return on plan assets		9.77%	10.44%
Rate of compensation increase		6.41%	6.44%

[1] (1)A U.S. subsidiary of the Company has defined benefit obligations of $6 million and $748 million as of December 31, 2015 and 2014, respectively, for which salary bands, rather than rates of compensation increases, are used to determine future benefit costs. Rates of compensation increases in the table above do not include amounts related to these specific defined benefit plans. A plan with a defined benefit obligation of $742 million at December 31, 2014 and which used salary bands at that date is using a rate of compensation increase as at December 31, 2015. The rate of compensation increase for this plan is included in the weighted average in the above table for calculating the benefit obligation as at December 31, 2015, but is not included in the weighted average for calculating the benefit obligation as at December 31, 2014 or the periodic benefit cost for 2014 or 2015.

[2] (2) Includes an inflation factor that is used to calculate future periodic benefit cost, but is not used to calculate the benefit obligation.