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]
Beginning Balances, value at Dec. 31, 2019	$ 1,014,832	$ 3,696	$ 512,019	$ 515,876	$ (16,759)
Balances, shares at Dec. 31, 2019		36,957
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	6,044		6,044
Shares repurchased and retired, value	(19,329)	$ (73)	(8,048)	(11,208)
Shares repurchased and retired, shares		(724)
Stock options exercised, value	364	$ 2	362
Stock options exercised, shares		17
Vesting of restricted stock units, value		$ 28	(28)
Vesting of restricted stock units, shares		283
Shares withheld for taxes, value	(1,801)	$ (7)	(1,794)
Shares withheld for taxes, shares		(72)
Dividends declared	(11,662)			(11,662)
Net income	445			445
Other comprehensive income (loss)	(4,533)				(4,533)
Ending Balances, value at Jun. 30, 2020	984,360	$ 3,646	508,555	493,451	(21,292)
Balances, shares at Jun. 30, 2020		36,461
Beginning Balances, value at Mar. 31, 2020	989,622	$ 3,642	505,283	502,692	(21,995)
Balances, shares at Mar. 31, 2020		36,415
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	3,305		3,305
Stock options exercised, value	5		5
Stock options exercised, shares		1
Vesting of restricted stock units, value		$ 4	(4)
Vesting of restricted stock units, shares		47
Shares withheld for taxes, value	(34)		(34)
Shares withheld for taxes, shares		(2)
Dividends declared	(5,834)			(5,834)
Net income	(3,407)			(3,407)
Other comprehensive income (loss)	703				703
Ending Balances, value at Jun. 30, 2020	984,360	$ 3,646	508,555	493,451	(21,292)
Balances, shares at Jun. 30, 2020		36,461
Beginning Balances, value at Dec. 31, 2020	$ 989,588	$ 3,629	510,405	492,205	(16,651)
Balances, shares at Dec. 31, 2020	36,295	36,295
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 6,863		6,863
Shares repurchased and retired, value	(30,319)	$ (99)	(11,227)	(18,993)
Shares repurchased and retired, shares		(1,008)
Stock options exercised, value	$ 346	$ 3	343
Stock options exercised, shares	54	29
Vesting of restricted stock units, value		$ 35	(35)
Vesting of restricted stock units, shares		351
Shares withheld for taxes, value	$ (2,973)	$ (10)	(2,963)
Shares withheld for taxes, shares		(101)
Dividends declared	(11,643)			(11,643)
Net income	15,286			15,286
Other comprehensive income (loss)	130				130
Ending Balances, value at Jun. 30, 2021	$ 967,278	$ 3,558	503,386	476,855	(16,521)
Balances, shares at Jun. 30, 2021	35,566	35,566
Beginning Balances, value at Mar. 31, 2021	$ 977,547	$ 3,608	505,659	486,267	(17,987)
Balances, shares at Mar. 31, 2021		36,062
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	4,013		4,013
Shares repurchased and retired, value	(17,267)	$ (57)	(6,300)	(10,910)
Shares repurchased and retired, shares		(567)
Stock options exercised, value	70		70
Stock options exercised, shares		4
Vesting of restricted stock units, value		$ 7	(7)
Vesting of restricted stock units, shares		69
Shares withheld for taxes, value	(49)		(49)
Shares withheld for taxes, shares		(2)
Dividends declared	(5,871)			(5,871)
Net income	7,369			7,369
Other comprehensive income (loss)	1,466				1,466
Ending Balances, value at Jun. 30, 2021	$ 967,278	$ 3,558	$ 503,386	$ 476,855	$ (16,521)
Balances, shares at Jun. 30, 2021	35,566	35,566