CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2020	$ 44,132	$ 555	$ 95,528	$ (626,984)	$ 575,033
Balance (shares) at Dec. 31, 2020		55,489
Purchase of treasury stock, at cost	(29,686)	$ 0	0	29,686	0
Stock-based compensation expense	11,822	0	10,851	971	0
Other	682	0	364	318	0
Dividends paid	(15,461)	0	0	0	(15,461)
Unrealized gain (loss) on marketable securities, net of tax	(7)	0	0	0	(7)
Net income	61,922	0	0	0	61,922
Balance at Mar. 31, 2021	73,644	$ 555	81,329	(628,391)	620,151
Balance (shares) at Mar. 31, 2021		55,489
Balance at Dec. 31, 2021	(1,774)	$ 555	109,179	(665,089)	553,581
Balance (shares) at Dec. 31, 2021		55,489
Purchase of treasury stock, at cost	(27,441)	$ 0	0	27,441	0
Issuance of equity-based incentive awards and dividend equivalents	0	0	(27)	28	(1)
Stock-based compensation expense	9,846	0	9,575	271	0
Other	782	0	513	269	0
Dividends paid	(17,244)	0	0	0	(17,244)
Unrealized gain (loss) on marketable securities, net of tax	(92)	0	0	0	(92)
Net income	69,884	0	0	0	69,884
Balance at Mar. 31, 2022	$ 33,961	$ 555	$ 110,053	$ (681,625)	$ 604,978
Balance (shares) at Mar. 31, 2022		55,489