Pension Plans and Other Postretirement Benefits - Assumed Weighted-Average Rates Used to Determine Benefit Obligations (Detail)	Dec. 31, 2023	Dec. 31, 2022
Pension Benefits [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Discount rate	5.00%	5.00%
Rate of increase in future compensation levels	3.32%	3.33%
Other Postretirement Benefits [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Discount rate	5.00%	5.00%