XML 92 R78.htm IDEA: XBRL DOCUMENT v3.22.0.1
Pension Plans and Postretirement Benefits - Assumed Health Care Cost Trend Rates (Detail)
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Retirement Benefits [Abstract]    
Health care cost trend rate assumed for next year 7.50% 6.75%
Rates to which the cost trend rate is assumed to decline (ultimate trend rate) 4.50% 4.50%
Year that the rate reaches ultimate trend rate 2034 2030