CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid In Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock	Accumulated  Other Comprehensive Loss
BEGINNING BALANCE (in shares) at Dec. 31, 2019			32,871,504
BEGINNING BALANCE at Dec. 31, 2019	$ 250,031	$ (1,190)	$ 329	$ 190,230	$ 173,371	$ (1,190)		$ (7,143)
BEGINING BALANCE, Treasury Stock (in shares) at Dec. 31, 2019							(2,855,164)
BEGINING BALANCE, Treasury Stock at Dec. 31, 2019							$ (106,756)
Net income	69,402				69,402
Issuance of common stock awards to employees (in shares)			249,435
Issuance of common stock awards to employees	0		$ 2	(2)
Surrender of common stock awards (in shares)							(29,069)
Surrender of common stock awards	(973)						$ (973)
Share-based compensation expense	7,029			7,029
Share-based compensation issued to directors (in shares)			6,371
Share-based compensation issued to directors	$ 229			229
Common stock repurchase (in shares)	(443,000)						(442,542)
Common stock repurchase	$ (15,759)						$ (15,759)
Other comprehensive income (loss), net of tax	(4,582)							(4,582)
ENDING BALANCE (in shares) at Sep. 30, 2020			33,127,310
ENDING BALANCE at Sep. 30, 2020	304,187		$ 331	197,486	241,583			(11,725)
ENDING BALANCE, Treasury Stock (in shares) at Sep. 30, 2020							(3,326,775)
ENDING BALANCE, Treasury Stock at Sep. 30, 2020							$ (123,488)
BEGINNING BALANCE (in shares) at Jun. 30, 2020			33,124,237
BEGINNING BALANCE at Jun. 30, 2020	272,736		$ 331	195,288	213,506			(12,901)
BEGINING BALANCE, Treasury Stock (in shares) at Jun. 30, 2020							(3,325,049)
BEGINING BALANCE, Treasury Stock at Jun. 30, 2020							$ (123,488)
Net income	28,077				28,077
Issuance of common stock awards to employees (in shares)			3,073
Issuance of common stock awards to employees	0
Surrender of common stock awards (in shares)							(1,726)
Surrender of common stock awards	0
Share-based compensation expense	2,094			2,094
Share-based compensation issued to directors (in shares)
Share-based compensation issued to directors	104			104
Other comprehensive income (loss), net of tax	1,176							1,176
ENDING BALANCE (in shares) at Sep. 30, 2020			33,127,310
ENDING BALANCE at Sep. 30, 2020	$ 304,187		$ 331	197,486	241,583			(11,725)
ENDING BALANCE, Treasury Stock (in shares) at Sep. 30, 2020							(3,326,775)
ENDING BALANCE, Treasury Stock at Sep. 30, 2020							$ (123,488)
BEGINNING BALANCE (in shares) at Dec. 31, 2020	33,141,879		33,141,879
BEGINNING BALANCE at Dec. 31, 2020	$ 319,182		$ 331	199,847	269,420			(8,763)
BEGINING BALANCE, Treasury Stock (in shares) at Dec. 31, 2020	(3,518,607)						(3,518,607)
BEGINING BALANCE, Treasury Stock at Dec. 31, 2020	$ (141,653)						$ (141,653)
Net income	89,396				89,396
Issuance of common stock awards to employees (in shares)			125,550
Issuance of common stock awards to employees	0		$ 2	(2)
Surrender of common stock awards (in shares)							(45,897)
Surrender of common stock awards	(5,575)						$ (5,575)
Share-based compensation expense	8,351			8,351
Share-based compensation issued to directors (in shares)			4,230
Share-based compensation issued to directors	339			339
Dividends declared	$ (26,729)				(26,729)
Common stock repurchase (in shares)	0
Other comprehensive income (loss), net of tax	$ 7,762							7,762
ENDING BALANCE (in shares) at Sep. 30, 2021	33,271,659		33,271,659
ENDING BALANCE at Sep. 30, 2021	$ 392,726		$ 333	208,535	332,087			(1,001)
ENDING BALANCE, Treasury Stock (in shares) at Sep. 30, 2021	(3,564,504)						(3,564,504)
ENDING BALANCE, Treasury Stock at Sep. 30, 2021	$ (147,228)						$ (147,228)
BEGINNING BALANCE (in shares) at Jun. 30, 2021			33,264,517
BEGINNING BALANCE at Jun. 30, 2021	362,540		$ 333	205,597	306,107			(2,293)
BEGINING BALANCE, Treasury Stock (in shares) at Jun. 30, 2021							(3,562,942)
BEGINING BALANCE, Treasury Stock at Jun. 30, 2021							$ (147,204)
Net income	34,892				34,892
Issuance of common stock awards to employees (in shares)			7,142
Issuance of common stock awards to employees	0
Surrender of common stock awards (in shares)							(1,562)
Surrender of common stock awards	(24)						$ (24)
Share-based compensation expense	2,812			2,812
Share-based compensation issued to directors (in shares)
Share-based compensation issued to directors	126			126
Dividends declared	(8,912)				(8,912)
Other comprehensive income (loss), net of tax	$ 1,292							1,292
ENDING BALANCE (in shares) at Sep. 30, 2021	33,271,659		33,271,659
ENDING BALANCE at Sep. 30, 2021	$ 392,726		$ 333	$ 208,535	$ 332,087			$ (1,001)
ENDING BALANCE, Treasury Stock (in shares) at Sep. 30, 2021	(3,564,504)						(3,564,504)
ENDING BALANCE, Treasury Stock at Sep. 30, 2021	$ (147,228)						$ (147,228)