Stockholders' Equity - Changes in Accumulated Other Comprehensive Loss, Net of Tax by Component (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 380,426	$ 446,279
Other comprehensive income (loss) before reclassifications	(2,581)	(929)
Amounts reclassified from accumulated other comprehensive income (loss)	1,189	75
Amounts reclassified to retained earnings		385
Net current period other comprehensive income (loss)	(1,392)	(469)
Ending Balance	363,715	443,547
ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	385
Amounts reclassified to retained earnings		385
Net current period other comprehensive income (loss)		385
Ending Balance	385	385
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(284)	(563)
Other comprehensive income (loss) before reclassifications	(931)	231
Amounts reclassified from accumulated other comprehensive income (loss)	1,048	(46)
Net current period other comprehensive income (loss)	117	185
Ending Balance	(167)	(378)
Defined Benefit Plan Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(9,226)	(8,041)
Amounts reclassified from accumulated other comprehensive income (loss)	141	121
Net current period other comprehensive income (loss)	141	121
Ending Balance	(9,085)	(7,920)
Foreign Currency Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(7,292)	(5,812)
Other comprehensive income (loss) before reclassifications	(1,650)	(1,160)
Net current period other comprehensive income (loss)	(1,650)	(1,160)
Ending Balance	(8,942)	(6,972)
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(16,417)	(14,416)
Ending Balance	$ (17,809)	$ (14,885)