Pensions and Other Post-retirement Benefits - Summary of Pension Plan Assets Measured at Fair Value on Recurring Basis by Fair Value Hierarchy (Detail) - Pension Plan - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Total	$ 638,963	$ 580,364	$ 563,449
Fair Value, Measurements, Recurring
Defined Benefit Plan Disclosure [Line Items]
Total	638,963	580,364
NAV	108,971	104,893
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total	446,719	416,892
Fair Value, Measurements, Recurring | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total	83,273	55,245
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total	0	3,334
Fair Value, Measurements, Recurring | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total	374,848	375,001
NAV	59,938	56,803
Fair Value, Measurements, Recurring | Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total	314,910	318,198
Fair Value, Measurements, Recurring | Equity securities | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Equity securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Total	210,277	152,258
NAV	0	0
Fair Value, Measurements, Recurring | Fixed income securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total	129,420	97,013
Fair Value, Measurements, Recurring | Fixed income securities | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total	80,857	55,245
Fair Value, Measurements, Recurring | Fixed income securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Pooled investment funds
Defined Benefit Plan Disclosure [Line Items]
Total	44,630	42,182
NAV	44,630	42,182
Fair Value, Measurements, Recurring | Pooled investment funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Pooled investment funds | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Pooled investment funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Total	2,416	3,334
NAV	0	0
Fair Value, Measurements, Recurring | Insurance contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Insurance contracts | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total	2,416	0
Fair Value, Measurements, Recurring | Insurance contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total	0	3,334
Fair Value, Measurements, Recurring | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total	6,792	7,589
NAV	4,403	5,908
Fair Value, Measurements, Recurring | Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total	2,389	1,681
Fair Value, Measurements, Recurring | Cash and cash equivalents | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Fair Value, Measurements, Recurring | Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total	$ 0	$ 0