CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Additional Paid-In Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-In Capital	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Total
Balances at Dec. 31, 2019	$ 288	$ 288	$ 333,943	$ 333,943	$ (198)	$ 532,989	$ 533,187	$ (104,578)	$ (104,578)	$ 203	$ 203	$ (198)	$ 762,845	$ 763,043
Balances (in shares) at Dec. 31, 2019	28,811	28,811						3,405	3,405
Increase (Decrease) in Stockholders' Equity
Net income							1,902							1,902
Other comprehensive income (loss), net of tax											(2,467)			(2,467)
Issuance of common stock under share-based compensation plans (in shares)		6
Tax effect of share-based compensation plans				(60)										(60)
Share-based compensation expense				2,181										2,181
Purchase of treasury stock									$ (3,162)					(3,162)
Purchase of treasury stock (in shares)									150
Dividends declared on common stock							(2,033)							(2,033)
Balances at Mar. 31, 2020		$ 288		336,064			532,858		$ (107,740)		(2,264)			759,206
Balances (in shares) at Mar. 31, 2020		28,817							3,555
Balances at Dec. 31, 2019	$ 288	$ 288	$ 333,943	333,943	$ (198)	$ 532,989	533,187	$ (104,578)	$ (104,578)	$ 203	203	$ (198)	$ 762,845	763,043
Balances (in shares) at Dec. 31, 2019	28,811	28,811						3,405	3,405
Increase (Decrease) in Stockholders' Equity
Net income														17,782
Other comprehensive income (loss), net of tax											(2,293)			(2,293)
Balances at Jun. 30, 2020		$ 290		337,942			546,689		$ (107,740)		(2,090)			775,091
Balances (in shares) at Jun. 30, 2020		28,958							3,555
Balances at Mar. 31, 2020		$ 288		336,064			532,858		$ (107,740)		(2,264)			759,206
Balances (in shares) at Mar. 31, 2020		28,817							3,555
Increase (Decrease) in Stockholders' Equity
Net income							15,880							15,880
Other comprehensive income (loss), net of tax											174			174
Issuance of common stock under share-based compensation plans		$ 2		(2)
Issuance of common stock under share-based compensation plans (in shares)		141
Tax effect of share-based compensation plans				(1,010)										(1,010)
Share-based compensation expense				2,890										2,890
Dividends declared on common stock							(2,049)							(2,049)
Balances at Jun. 30, 2020		$ 290		337,942			546,689		$ (107,740)		(2,090)			775,091
Balances (in shares) at Jun. 30, 2020		28,958							3,555
Balances at Dec. 31, 2020		$ 290		342,354			595,932		$ (111,173)		1,190			828,593
Balances (in shares) at Dec. 31, 2020		29,045							3,657
Increase (Decrease) in Stockholders' Equity
Net income							23,361							23,361
Other comprehensive income (loss), net of tax											804			804
Issuance of common stock under share-based compensation plans		$ 1		(1)
Issuance of common stock under share-based compensation plans (in shares)		12
Tax effect of share-based compensation plans				(165)										(165)
Share-based compensation expense				2,354										2,354
Purchase of treasury stock									$ (1,001)					(1,001)
Purchase of treasury stock (in shares)									15
Dividends declared on common stock							(2,037)							(2,037)
Balances at Mar. 31, 2021		$ 291		344,542			617,256		$ (112,174)		1,994			851,909
Balances (in shares) at Mar. 31, 2021		29,057							3,672
Balances at Dec. 31, 2020		$ 290		342,354			595,932		$ (111,173)		1,190			828,593
Balances (in shares) at Dec. 31, 2020		29,045							3,657
Increase (Decrease) in Stockholders' Equity
Net income														84,342
Other comprehensive income (loss), net of tax											1,482			1,482
Balances at Jun. 30, 2021		$ 293		338,263			676,179		$ (119,273)		2,672			898,134
Balances (in shares) at Jun. 30, 2021		29,318							3,783
Balances at Mar. 31, 2021		$ 291		344,542			617,256		$ (112,174)		1,994			851,909
Balances (in shares) at Mar. 31, 2021		29,057							3,672
Increase (Decrease) in Stockholders' Equity
Net income							60,981							60,981
Other comprehensive income (loss), net of tax											678			678
Issuance of common stock under share-based compensation plans		$ 2		(2)
Issuance of common stock under share-based compensation plans (in shares)		261
Tax effect of share-based compensation plans				(9,601)										(9,601)
Share-based compensation expense				3,324										3,324
Purchase of treasury stock									$ (7,099)					(7,099)
Purchase of treasury stock (in shares)									111
Dividends declared on common stock							(2,058)							(2,058)
Balances at Jun. 30, 2021		$ 293		$ 338,263			$ 676,179		$ (119,273)		$ 2,672			$ 898,134
Balances (in shares) at Jun. 30, 2021		29,318							3,783