Pensions and Other Post-retirement Benefits - Schedule of Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Assumptions used to determine benefit obligations, average discount rate	5.37%	5.35%
Assumptions used to determine benefit obligations, rate of compensation increase	2.97%	2.96%
Assumptions used to determine net periodic benefit cost, average discount rate, service cost	5.75%	5.02%
Assumptions used to determine net periodic benefit cost, average discount rate, interest cost	5.07%	4.64%
Assumptions used to determine net periodic benefit cost, expected return on plan assets	8.05%	7.23%
Assumptions used to determine net periodic benefit cost, rate of compensation increase	2.96%	3.78%
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Assumptions used to determine benefit obligations, average discount rate	5.09%	5.49%
Assumptions used to determine benefit obligations, rate of compensation increase	3.00%	3.00%
Assumptions used to determine net periodic benefit cost, average discount rate, service cost	5.65%	4.96%
Assumptions used to determine net periodic benefit cost, average discount rate, interest cost	5.22%	4.85%
Assumptions used to determine net periodic benefit cost, expected return on plan assets	0.00%	0.00%
Assumptions used to determine net periodic benefit cost, rate of compensation increase	3.00%	3.00%