XML 212 R156.htm IDEA: XBRL DOCUMENT v3.20.4
Employee Benefit Plans (Assumed Health Care Cost Trend Rates) (Details)
Dec. 31, 2020
Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]    
Health care cost trend rate assumed for next year 6.25% 6.00%
Rate to which the cost trend is assumed to decline (the ultimate trend rate) 4.75% 4.75%