Pension and Postretirement Benefits - Summary of Funded Status of the Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Domestic Plans
Change in plan assets:
Fair value of plan assets at beginning of year	$ 11,291
Fair value of plan assets at end of year	11,878	$ 11,291
Foreign Pension Plans
Change in benefit obligation:
Service cost	444	405	$ 552
Interest cost	365	397	381
Actuarial adjustments	368	605	(238)
Change in plan assets:
Fair value of plan assets at beginning of year	10,013
Fair value of plan assets at end of year	10,798	10,013
Foreign Pension Plans | Funded Plans
Change in benefit obligation:
Benefit obligation at beginning of year	9,990	8,134
Service cost	444	405
Interest cost	295	320
Actuarial adjustments	686	1,037
Benefits paid	(743)	(336)
Translation adjustment	244	430
Benefit obligation at end of year	10,916	9,990	8,134
Change in plan assets:
Fair value of plan assets at beginning of year	10,013	8,243
Actual return on plan assets	1,044	1,156
Company contributions	253	515
Benefits paid	(743)	(336)
Translation adjustment	231	435
Fair value of plan assets at end of year	10,798	10,013	8,243
Funded status at end of year	(118)	23
Foreign Pension Plans | Unfunded Pension Plans
Change in benefit obligation:
Benefit obligation at beginning of year	2,331	2,290
Interest cost	70	77
Actuarial adjustments	111	106
Benefits paid	(180)	(178)
Translation adjustment	117	36
Benefit obligation at end of year	2,449	2,331	2,290
Change in plan assets:
Company contributions	180	178
Benefits paid	(180)	(178)
Funded status at end of year	(2,449)	(2,331)
Pension Plans | Domestic Plans
Change in benefit obligation:
Service cost		61	64
Interest cost	653	861	780
Actuarial adjustments	1,587	1,305	(76)
Pension Plans | Domestic Plans | Funded Plans
Change in benefit obligation:
Benefit obligation at beginning of year	15,572	14,235
Interest cost	406	527
Actuarial adjustments	1,242	1,611
Benefits paid	(889)	(801)
Benefit obligation at end of year	16,331	15,572	14,235
Change in plan assets:
Fair value of plan assets at beginning of year	11,291	10,299
Actual return on plan assets	584	1,157
Company contributions	892	636
Benefits paid	(889)	(801)
Fair value of plan assets at end of year	11,878	11,291	10,299
Funded status at end of year	(4,453)	(4,281)
Pension Plans | Domestic Plans | Unfunded Pension Plans
Change in benefit obligation:
Benefit obligation at beginning of year	9,462	9,271
Service cost		61
Interest cost	247	333
Actuarial adjustments	784	753
Benefits paid	(717)	(956)
Benefit obligation at end of year	9,776	9,462	9,271
Change in plan assets:
Company contributions	717	956
Benefits paid	(717)	(956)
Funded status at end of year	(9,776)	(9,462)
Postretirement Benefit Plans
Change in benefit obligation:
Benefit obligation at beginning of year	11,986	13,454
Service cost	51	64
Interest cost	296	458
Actuarial adjustments	688	(1,117)
Benefits paid	(802)	(873)
Benefit obligation at end of year	12,219	11,986	13,454
Change in plan assets:
Company contributions	802	873
Benefits paid	(802)	(873)
Funded status at end of year	(12,219)	(11,986)
Postretirement Benefit Plans | Domestic Plans
Change in benefit obligation:
Service cost	51	64	80
Interest cost	296	458	449
Actuarial adjustments	$ 688	$ (1,117)	$ 170