CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Shares	Total
Balance at Dec. 31, 2020	$ 289	$ 119,891	$ 562,084	$ (45,937)	$ 636,327
Balance (in shares) at Dec. 31, 2020	28,943			(2,773)
Stock-based compensation expense		3,118			3,118
Restricted stock units vested	$ 1	(1)
Restricted stock units vested (in shares)	35
Shares withheld for taxes paid on stock awards		(794)			(794)
Net income			47,521		47,521
Balance at Sep. 30, 2021	$ 290	122,214	609,605	$ (45,937)	686,172
Balance (in shares) at Sep. 30, 2021	28,978			(2,773)
Balance at Jun. 30, 2021	$ 289	121,659	589,560	$ (45,937)	665,571
Balance (in shares) at Jun. 30, 2021	28,960			(2,773)
Stock-based compensation expense		1,026			1,026
Restricted stock units vested	$ 1	(1)
Restricted stock units vested (in shares)	18
Shares withheld for taxes paid on stock awards		(470)			(470)
Net income			20,045		20,045
Balance at Sep. 30, 2021	$ 290	122,214	609,605	$ (45,937)	686,172
Balance (in shares) at Sep. 30, 2021	28,978			(2,773)
Balance at Dec. 31, 2021	$ 290	122,354	605,766	$ (45,937)	682,473
Balance (in shares) at Dec. 31, 2021	29,025			(2,773)
Stock-based compensation expense		4,072			4,072
Restricted stock units vested	$ 1	(1)
Restricted stock units vested (in shares)	36
Shares withheld for taxes paid on stock awards		(834)			(834)
Net income			70,396		70,396
Balance at Sep. 30, 2022	$ 291	125,591	676,162	$ (45,937)	756,107
Balance (in shares) at Sep. 30, 2022	29,061			(2,773)
Balance at Jun. 30, 2022	$ 290	124,690	652,956	$ (45,937)	731,999
Balance (in shares) at Jun. 30, 2022	29,045			(2,773)
Stock-based compensation expense		1,282			1,282
Restricted stock units vested	$ 1	(1)
Restricted stock units vested (in shares)	16
Shares withheld for taxes paid on stock awards		(380)			(380)
Net income			23,206		23,206
Balance at Sep. 30, 2022	$ 291	$ 125,591	$ 676,162	$ (45,937)	$ 756,107
Balance (in shares) at Sep. 30, 2022	29,061			(2,773)