Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 1,410	$ (2,416)	$ 9,804	$ 4,990
Foreign currency translation adjustments	3,846	5,891	(9,347)	(8,012)
Net change in:
Deferred gains (losses) on cash flow hedges, net of taxes of $114, $295, $(1,187) and $696, respectively	(316)	(552)	2,945	(1,869)
Unrecognized retirement obligations, net of taxes of $(14), $52, $(87) and $103, respectively	150	(99)	242	(200)
Other comprehensive income (loss)	3,680	5,240	(6,160)	(10,081)
Comprehensive income (loss)	$ 5,090	$ 2,824	$ 3,644	$ (5,091)