Employee Benefit Plans and Equity Compensation Plan (Significant Assumptions Used to Determine Benefit Obligations) (Detail)	Dec. 31, 2023	Dec. 31, 2022
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Annual discount rate used to determine benefit obligation	5.39%	5.69%
Assumed annual rate of future salary increases for projected benefit obligation	3.54%	3.93%
Crediting interest rate for cash balance plans	4.14%	4.44%
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Annual discount rate used to determine benefit obligation	5.42%	5.70%