Benefit Obligations (Plan Assets Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		6.50%	6.70%	7.30%
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
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Actual return on plan assets		16.60%
Expected return on plan assets		6.70%	6.80%	7.50%
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		5.60%	5.90%	5.90%
Forecast [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.70%