Postretirement Benefit Plans - Actuarial Assumptions Used to Determine Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jun. 26, 2022
Qualified Defined  Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	5.00%	5.25%	2.875%	4.75%
Expected long-term rate of return on assets	6.50%	6.50%	6.50%
Retiree Medical and Life Insurance Plans
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate	5.00%	5.25%	2.75%
Expected long-term rate of return on assets	6.50%	6.50%	6.50%
Health care trend rate assumed for next year	8.00%	7.25%	7.50%
Ultimate health care trend rate	4.50%	4.50%	4.50%