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Stockholders' Equity - Changes in Accumulated Other Comprehensive Loss, Net of Tax by Component (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Beginning Balance | $ 370,375 | $ 363,715 | $ 372,944 | $ 380,426
Other comprehensive income (loss) before reclassifications | 66 | 2,780 | (1,854) | 199
Amounts reclassified from accumulated other comprehensive income (loss) | 389 | (317) | 353 | 872
Net current period other comprehensive income (loss) | 455 | 2,463 | (1,501) | 1,071
Ending Balance | 375,515 | 364,194 | 375,515 | 364,194
ASU 2018-02 [Member] |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Beginning Balance | 385 | 385 | 385 | 385
Ending Balance | 385 | 385 | 385 | 385
Accumulated Other Comprehensive Income [Member] |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Beginning Balance | (13,595) | (17,809) | (11,639) | (16,417)
Ending Balance | (13,140) | (15,346) | (13,140) | (15,346)
Unrealized Gains (Losses) on Available-for-Sale Securities [Member] |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Beginning Balance | (160) | (167) | 32 | (284)
Other comprehensive income (loss) before reclassifications | (272) | 881 | (329) | (50)
Amounts reclassified from accumulated other comprehensive income (loss) | 177 | (508) | 42 | 540
Net current period other comprehensive income (loss) | (95) | 373 | (287) | 490
Ending Balance | (255) | 206 | (255) | 206
Defined Benefit Plan Adjustments [Member] |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Beginning Balance | (9,522) | (9,085) | (9,621) | (9,226)
Amounts reclassified from accumulated other comprehensive income (loss) | 212 | 191 | 311 | 332
Net current period other comprehensive income (loss) | 212 | 191 | 311 | 332
Ending Balance | (9,310) | (8,894) | (9,310) | (8,894)
Foreign Currency Adjustments [Member] |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Beginning Balance | (4,298) | (8,942) | (2,435) | (7,292)
Other comprehensive income (loss) before reclassifications | 338 | 1,899 | (1,525) | 249
Net current period other comprehensive income (loss) | 338 | 1,899 | (1,525) | 249
Ending Balance | $ (3,960) | $ (7,043) | $ (3,960) | $ (7,043)

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