Pension and Other Postretirement Benefit Plans (Schedule of Health Care Cost Trend Rates) (Details) - Other Postretirement Benefits	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate for next year (as a percent)	5.65%	5.83%
Rate to which the cost trend is assumed to decline (ultimate trend rate) (as a percent)	4.50%	4.50%