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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 363,715	$ 443,547	$ 380,426	$ 446,279
Other comprehensive income (loss) before reclassifications	2,780	713	199	(216)
Amounts reclassified from accumulated other comprehensive income (loss)	(317)	77	872	152
Amounts reclassified to retained earnings				385
Net current period other comprehensive income (loss)	2,463	790	1,071	321
Ending Balance	364,194	445,975	364,194	445,975
ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	385	385	385
Amounts reclassified to retained earnings				385
Net current period other comprehensive income (loss)				385
Ending Balance	385	385	385	385
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(167)	(378)	(284)	(563)
Other comprehensive income (loss) before reclassifications	881	180	(50)	411
Amounts reclassified from accumulated other comprehensive income (loss)	(508)	(73)	540	(119)
Net current period other comprehensive income (loss)	373	107	490	292
Ending Balance	206	(271)	206	(271)
Defined Benefit Plan Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(9,085)	(7,920)	(9,226)	(8,041)
Amounts reclassified from accumulated other comprehensive income (loss)	191	150	332	271
Net current period other comprehensive income (loss)	191	150	332	271
Ending Balance	(8,894)	(7,770)	(8,894)	(7,770)
Foreign Currency Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(8,942)	(6,972)	(7,292)	(5,812)
Other comprehensive income (loss) before reclassifications	1,899	533	249	(627)
Net current period other comprehensive income (loss)	1,899	533	249	(627)
Ending Balance	(7,043)	(6,439)	(7,043)	(6,439)
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(17,809)	(14,885)	(16,417)	(14,416)
Ending Balance	$ (15,346)	$ (14,095)	$ (15,346)	$ (14,095)

Cumulative effect on reclassification from AOCI to retained earnings due to changes in accounting standard.

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Other comprehensive income loss net of tax due to changes in accounting standard.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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