Schedule of Reconciliation of Defined Benefit Pension Plan (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Pension Plans And Defined Benefit Postretirement Plans Disclosure [Abstract]
Fair value of plan assets at beginning of year	$ 106,839	$ 116,697
Actual return (loss) on plan assets	8,858	(3,223)
Benefits paid	(5,651)	(6,086)
Administrative expenses	(369)	(549)
Fair value of plan assets at end of year	109,677	106,839	$ 116,697
Benefit obligation at beginning of year	118,180	127,342
Service cost	926	1,051	966
Interest cost	4,997	4,912
Actuarial (gain) loss	(7,503)	(9,039)
Benefit obligation at end of year	110,949	118,180	$ 127,342
Other non-current liabilities	1,272	11,341
Total amounts recognized at end of year	$ 1,272	$ 11,341