Condensed Consolidated Statements Of Shareholders' Equity (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Balances, shares at Dec. 31, 2018		41,357
Shares repurchased and retired, shares		(3,908)
Stock options exercised, shares		33
Vesting of restricted stock units, shares		242
Shares withheld for taxes, shares		(45)
Balances, shares at Jun. 30, 2019		37,679
Beginning Balances, value at Dec. 31, 2018	$ 1,132,225	$ 4,136	$ 554,939	$ 584,274	$ (11,124)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	5,720	0	5,720	0	0
Shares repurchased and retired, value	(100,039)	(391)	(43,424)	(56,224)	0
Stock options exercised, value	693	3	690	0	0
Vesting of restricted stock units, value	0	24	(24)	0	0
Shares withheld for taxes, value	(1,242)	(4)	(1,238)	0	0
Dividends declared	(11,527)	0	0	(11,527)	0
Net income (loss)	23,220	0	0	23,220	0
Other comprehensive income (loss)	(4,000)	0	0	0	(4,000)
Ending Balances, value at Jun. 30, 2019	1,045,050	$ 3,768	516,663	539,743	(15,124)
Balances, shares at Mar. 31, 2019		39,169
Shares repurchased and retired, shares		(1,525)
Stock options exercised, shares		20
Vesting of restricted stock units, shares		15
Shares withheld for taxes, shares		0
Balances, shares at Jun. 30, 2019		37,679
Beginning Balances, value at Mar. 31, 2019	1,078,725	$ 3,917	530,261	557,804	(13,257)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2,948	0	2,948	0	0
Shares repurchased and retired, value	(38,959)	(152)	(16,951)	(21,856)	0
Stock options exercised, value	414	2	412	0	0
Vesting of restricted stock units, value	0	1	(1)	0	0
Shares withheld for taxes, value	(6)	0	(6)	0	0
Dividends declared	(5,652)	0	0	(5,652)	0
Net income (loss)	9,447	0	0	9,447	0
Other comprehensive income (loss)	(1,867)	0	0	0	(1,867)
Ending Balances, value at Jun. 30, 2019	$ 1,045,050	$ 3,768	516,663	539,743	(15,124)
Balances, shares at Dec. 31, 2019	36,957	36,957
Shares repurchased and retired, shares		(724)
Stock options exercised, shares		17
Vesting of restricted stock units, shares		283
Shares withheld for taxes, shares		(72)
Balances, shares at Jun. 30, 2020	36,461	36,461
Beginning Balances, value at Dec. 31, 2019	$ 1,014,832	$ 3,696	512,019	515,876	(16,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	6,044	0	6,044	0	0
Shares repurchased and retired, value	(19,329)	(73)	(8,048)	(11,208)	0
Stock options exercised, value	364	2	362	0	0
Vesting of restricted stock units, value	0	28	(28)	0	0
Shares withheld for taxes, value	(1,801)	(7)	(1,794)	0	0
Dividends declared	(11,662)	0	0	(11,662)	0
Net income (loss)	445	0	0	445	0
Other comprehensive income (loss)	(4,533)	0	0	0	(4,533)
Ending Balances, value at Jun. 30, 2020	$ 984,360	$ 3,646	508,555	493,451	(21,292)
Balances, shares at Mar. 31, 2020		36,415
Shares repurchased and retired, shares		0
Stock options exercised, shares		1
Vesting of restricted stock units, shares		47
Shares withheld for taxes, shares		(2)
Balances, shares at Jun. 30, 2020	36,461	36,461
Beginning Balances, value at Mar. 31, 2020	$ 989,622	$ 3,642	505,283	502,692	(21,995)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	3,305	0	3,305	0	0
Stock options exercised, value	5	0	5	0	0
Vesting of restricted stock units, value	0	4	(4)	0	0
Shares withheld for taxes, value	(34)	0	(34)	0	0
Dividends declared	(5,834)	0	0	(5,834)	0
Net income (loss)	(3,407)	0	0	(3,407)	0
Other comprehensive income (loss)	703	0	0	0	703
Ending Balances, value at Jun. 30, 2020	$ 984,360	$ 3,646	$ 508,555	$ 493,451	$ (21,292)