v3.25.4
Basis of Presentation and Significant Accounting Policies - Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Sep. 30, 2024
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Revenues $ 885,842 $ 866,286 $ 764,039 $ 682,258 $ 746,267 $ 671,956 $ 681,465 $ 603,966 $ 3,198,425 $ 2,703,654 $ 2,496,309
Cost of operations                 (2,465,566) (2,048,447) (1,875,716)
Total before tax                 398,120 348,720 321,400
Provision for Income Taxes                 (68,259) (66,422) (75,079)
Net income                 329,861 282,298 246,321
Accumulated Other Comprehensive Income Component Recognized                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Net income                 (1,314) (2,247) (2,405)
Accumulated Other Comprehensive Income Component Recognized | Realized gain on derivative financial instruments                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Revenues                 51 (96) (72)
Cost of operations                 1,284 1,075 427
Total before tax                 1,335 979 355
Provision for Income Taxes                 (339) (245) (91)
Net income                 996 734 264
Accumulated Other Comprehensive Income Component Recognized | Amortization of prior service cost on benefit obligations                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Other – net                 (3,239) (3,325) (3,278)
Provision for Income Taxes                 629 344 609
Net income                 (2,610) (2,981) (2,669)
Accumulated Other Comprehensive Income Component Recognized | Realized gains on investments                      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                      
Other – net                 380 0 0
Provision for Income Taxes                 (80) 0 0
Net income                 $ 300 $ 0 $ 0