Pension and Other Postretirement Benefit Plans Pension and Other Postretirement Benefit Plans (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Pension and Other Postretirement Benefit Plans (Narrative) [Abstract]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year, Description	$ 220
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 170