XML 57 R96.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Pension and Other Postretirement Benefit Plans - Summary of Health Care Cost Trend Rate Assumptions for Other Postretirement Benefit Plans (Details) - Other Postretirement Benefits
Dec. 31, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]    
Health care cost trend rate assumed for next year 6.80% 7.00%
Rate to which the cost trend rate is assumed to decline 4.50% 4.50%