Schedule of Reconciliation of Defined Benefit Pension Plan (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]
Fair value of plan assets at beginning of year	$ 104,591	$ 118,667
Actual return (loss) on plan assets	22,331	(7,522)
Benefits paid	(6,168)	(6,031)
Administrative expenses	(467)	(523)
Fair value of plan assets at end of year	120,287	104,591	$ 118,667
Benefit obligation at beginning of year	108,428	116,056
Service cost	725	689	721
Interest cost	4,237	4,063	4,465
Benefits paid	(6,168)	(6,031)
Actuarial (gain) loss	10,334	(6,349)
Benefit obligation at end of year	117,556	108,428	$ 116,056
Other non-current assets	2,731
Other non-current liabilities		3,836
Total amounts recognized at end of year	$ 2,731	$ 3,836