Benefit Obligations (Plan Assets Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		7.30%	7.30%	7.80%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 23
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 5
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual return on plan assets		11.40%
Expected return on plan assets		7.50%	7.50%	8.00%
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		5.90%	6.10%	6.00%
Scenario, Forecast [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.80%