Interim Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	AdditionalPaid-in Capital	Treasury Stock	Retained Earnings	AccumulatedOtherComprehensive Loss
Beginning balance ( in shares) at Dec. 31, 2019		11,670
Beginning balance at Dec. 31, 2019	$ 569,757	$ 1,175	$ 113,666	$ (4,566)	$ 500,320	$ (40,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income	(9,122)				15,528	(24,650)
Stock-based compensation expense	933		933
Stock-based compensation transactions (in shares)		9
Stock-based compensation transactions	369	$ 1	368
Dividends paid	(1,528)				(1,528)
Ending balance (in shares) at Mar. 31, 2020		11,679
Ending balance at Mar. 31, 2020	560,409	$ 1,176	114,967	(4,566)	514,320	(65,488)
Beginning balance ( in shares) at Dec. 31, 2020		11,727
Beginning balance at Dec. 31, 2020	625,643	$ 1,181	118,528	(4,566)	550,826	(40,326)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income	15,876				17,462	(1,586)
Stock-based compensation expense	1,240		1,240
Stock-based compensation transactions (in shares)		29
Stock-based compensation transactions	776	$ 3	773
Dividends paid	(1,654)				(1,654)
Ending balance (in shares) at Mar. 31, 2021		11,756
Ending balance at Mar. 31, 2021	$ 641,881	$ 1,184	$ 120,541	$ (4,566)	$ 566,634	$ (41,912)