Postretirement Benefit Plans - Defined Contribution Plan Expenses for Company's Qualified Contribution Plans (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Defined Contribution Plan Disclosure [Line Items] | ||||
| Total defined contribution plan expenses | $ 2,839 | $ 2,979 | $ 6,164 | $ 5,952 |
| Retirement Savings Contributions [Member] | ||||
| Defined Contribution Plan Disclosure [Line Items] | ||||
| Total defined contribution plan expenses | 2,344 | 2,295 | 4,559 | 4,420 |
| Profit Sharing Contributions [Member] | ||||
| Defined Contribution Plan Disclosure [Line Items] | ||||
| Total defined contribution plan expenses | $ 495 | $ 684 | $ 1,605 | $ 1,532 |