Estimated Funded Status (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 6,946	$ 7,308
Service cost	31	26	$ 50
Interest cost	37	54	62
Actuarial (gain) loss	137	471
Benefits paid	(322)	(636)
Curtailment	0	(346)
Other	0	0
Foreign exchange impact	449	69
Benefit obligation at end of year	7,278	6,946	7,308
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	910	835
Return on plan assets	31	35
Employer contributions	73	93
Benefits paid	(41)	(63)
Foreign exchange impact	69	10
Fair value of plan assets at end of year	1,042	910	$ 835
Plan assets less than benefit obligation - Net amount recognized	$ (6,236)	$ (6,036)