Income Taxes - Earnings Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings before income taxes
Earnings before income taxes	$ 45,479	$ 50,266	$ 58,103
U.S.
Earnings before income taxes
Earnings before income taxes	(7,101)	15,103	30,815
Non-U.S.
Earnings before income taxes
Earnings before income taxes	$ 52,580	$ 35,163	$ 27,288