Retirement Plans (Retirement Plans, Net Periodic Benefit Cost, Assumptions, and Expected Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 865	$ 872
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	15
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost	$ 30	$ 42	$ 36
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	8	9
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Number of years annual benefit payments	10 years
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 15
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	55
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	46
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	49
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	50
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	54
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	317
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 865	$ 872
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	2.90%	4.20%
Rate of compensation increase	4.80%	5.40%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.20%	4.10%	4.80%
Expected long-term return on plan assets	5.30%	5.90%	6.40%
Rate of compensation increase	5.40%	5.30%	5.40%
Real Estate Funds [Member] | Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 71	$ 88
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5	2
Fair Value, Inputs, Level 1 [Member] | Real Estate Funds [Member] | Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 0	$ 0