Other, Net - Other Net in Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Nonoperating Income Expense [Abstract]
Foreign exchange gains (losses)	$ 123	$ 1,902	$ (646)
Investment income	968	1,554	989
Realized and unrealized gains (losses) on investments	3,955	(2,966)	4,178
Net periodic benefit cost	(351)	(1,215)	(1,035)
Gain on sale of asset	570
Other retirement obligation	(694)
Other, net	$ 4,571	$ (725)	$ 3,486