Nature of Business - Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax by Components Of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 446,279	$ 497,911	$ 479,517
Other comprehensive income (loss) before reclassifications	(2,624)	(7,441)	10,851
Amounts reclassified to retained earnings	385	(3,220)
Amounts reclassified from accumulated other comprehensive loss	238	(460)	(1,958)
Ending Balance	380,426	446,279	497,911
ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified to retained earnings	385
Ending Balance	385
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(563)	2,567	404
Other comprehensive income (loss) before reclassifications	573	685	5,020
Amounts reclassified to retained earnings		(3,220)
Amounts reclassified from accumulated other comprehensive loss	(294)	(595)	(2,857)
Ending Balance	(284)	(563)	2,567
Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications			(619)
Amounts reclassified from accumulated other comprehensive loss			619
Defined Benefit Plan Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(8,041)	(4,286)	(5,017)
Other comprehensive income (loss) before reclassifications	(1,717)	(3,890)	451
Amounts reclassified from accumulated other comprehensive loss	532	135	280
Ending Balance	(9,226)	(8,041)	(4,286)
Foreign Currency Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(5,812)	(1,576)	(7,575)
Other comprehensive income (loss) before reclassifications	(1,480)	(4,236)	5,999
Ending Balance	(7,292)	(5,812)	(1,576)
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(14,416)	(3,295)	(12,188)
Ending Balance	$ (16,417)	$ (14,416)	$ (3,295)

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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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