Pension plan and 401(k) Program - Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Change in plan assets:
Fair value of plan assets, beginning of year	$ 23,610	$ 24,281
Actual return on plan assets	(332)	(409)
Participant contributions	832	753
Employer contributions	2,055	1,503
Benefits paid	(707)	(2,446)
Translation adjustments and other	453	(72)
Fair value of plan assets, end of year	$ 25,911	$ 23,610