CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Total
Balance at Dec. 31, 2020	$ 191	$ 34,498	$ 342,250	$ (8,872)	$ 368,067
Balance (in shares) at Dec. 31, 2020	18,426,130
Increase (Decrease) in Stockholders' Equity
Exercise of stock options, net		1,143		1,266	2,409
Exercise of stock options, net (in shares)	91,831
Stock-based compensation expense		1,280			1,280
Net income			8,154		8,154
Balance at Mar. 31, 2021	$ 191	36,921	350,404	(7,606)	379,910
Balance (in shares) at Mar. 31, 2021	18,517,961
Balance at Dec. 31, 2020	$ 191	34,498	342,250	(8,872)	368,067
Balance (in shares) at Dec. 31, 2020	18,426,130
Increase (Decrease) in Stockholders' Equity
Net income					26,303
Balance at Jun. 30, 2021	$ 191	38,843	368,553	(6,500)	401,087
Balance (in shares) at Jun. 30, 2021	18,599,516
Balance at Mar. 31, 2021	$ 191	36,921	350,404	(7,606)	379,910
Balance (in shares) at Mar. 31, 2021	18,517,961
Increase (Decrease) in Stockholders' Equity
Exercise of stock options, net		675		1,106	1,781
Exercise of stock options, net (in shares)	81,555
Stock-based compensation expense		1,247			1,247
Net income			18,149		18,149
Balance at Jun. 30, 2021	$ 191	38,843	368,553	(6,500)	401,087
Balance (in shares) at Jun. 30, 2021	18,599,516
Balance at Dec. 31, 2021	$ 191	41,426	410,738	(4,341)	$ 448,014
Balance (in shares) at Dec. 31, 2021	18,764,540				18,764,540
Increase (Decrease) in Stockholders' Equity
Exercise of stock options, net		19		2,458	$ 2,477
Exercise of stock options, net (in shares)	191,035
Restricted stock granted		1,658		262	1,920
Restricted stock granted, shares	19,549
Purchase of company common stock				(6,500)	(6,500)
Purchase of company common stock, shares	(100,000)
Stock-based compensation expense		1,160			1,160
Net income			18,118		18,118
Balance at Mar. 31, 2022	$ 191	44,263	428,856	(8,121)	465,189
Balance (in shares) at Mar. 31, 2022	18,875,124
Balance at Dec. 31, 2021	$ 191	41,426	410,738	(4,341)	$ 448,014
Balance (in shares) at Dec. 31, 2021	18,764,540				18,764,540
Increase (Decrease) in Stockholders' Equity
Net income					$ 37,553
Balance at Jun. 30, 2022	$ 191	45,802	448,291	(7,948)	$ 486,336
Balance (in shares) at Jun. 30, 2022	18,888,070				18,888,070
Balance at Mar. 31, 2022	$ 191	44,263	428,856	(8,121)	$ 465,189
Balance (in shares) at Mar. 31, 2022	18,875,124
Increase (Decrease) in Stockholders' Equity
Exercise of stock options, net		303		134	437
Exercise of stock options, net (in shares)	10,000
Restricted stock granted		211		39	250
Restricted stock granted, shares	2,946
Stock-based compensation expense		1,025			1,025
Net income			19,435		19,435
Balance at Jun. 30, 2022	$ 191	$ 45,802	$ 448,291	$ (7,948)	$ 486,336
Balance (in shares) at Jun. 30, 2022	18,888,070				18,888,070