CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - UNAUDITED - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Adjustments due to adoption of new accounting standards	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Accumulated Earnings	Accumulated Earnings Adjustments due to adoption of new accounting standards	Noncontrolling Interest
Balance, beginning of period, shares at Dec. 31, 2021		32,495,000
Balance, beginning of period at Dec. 31, 2021	$ 440,244	$ 705	$ 488,303		$ (930,106)	$ (38,353)	$ 916,060		$ 3,635
Net income	6,113						6,113
Unrealized gain (loss) on short-term investments, net of tax	(2)					(2)
Foreign currency translation adjustments	(1,182)					(1,182)
Total comprehensive income, net of tax	4,929
Repurchase of common stock	(23,801)	$ (1)	(7,804)		(15,996)
Repurchase of common stock, shares		(389,000)
Issuance of common stock pursuant to employee stock purchase plan	650		650
Issuance of common stock pursuant to employee stock purchase plan, shares		12,000
Issuance of restricted common stock pursuant to stock-based compensation plans		$ 5	(5)
Issuance of restricted common stock pursuant to stock-based compensation plans, shares		476,000
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares		(34,000)
Stock-based compensation expense	5,581		5,581
Settlement of convertible debt securities, net of tax	(4,845)		(4,845)
Dividends	(8,586)						(8,586)
Balance, ending of period, shares at Mar. 31, 2022		32,560,000
Balance, ending of period at Mar. 31, 2022	$ 414,172	$ 709	472,078	$ (9,802)	(946,102)	(39,537)	923,389	$ 9,802	$ 3,635
Balance, beginning of period, shares at Dec. 31, 2022	31,269,000	31,269
Balance, beginning of period at Dec. 31, 2022	$ 355,249	$ 708	495,189		(1,018,034)	(58,829)	936,215
Net income	20,928						20,928
Unrealized gain (loss) on short-term investments, net of tax	0
Foreign currency translation adjustments	2,843					2,843
Total comprehensive income, net of tax	23,771
Repurchase of common stock	(9,306)	$ (2)	(9,304)
Repurchase of common stock, shares		(166)
Issuance of common stock pursuant to employee stock purchase plan	893		893
Issuance of common stock pursuant to employee stock purchase plan, shares		19
Issuance of restricted common stock pursuant to stock-based compensation plans		$ 6	(6)
Issuance of restricted common stock pursuant to stock-based compensation plans, shares		574
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares		(18,000)
Stock-based compensation expense	6,412		6,412
Dividends	$ (8,796)						(8,796)
Balance, ending of period, shares at Mar. 31, 2023	31,678,000	31,678,000
Balance, ending of period at Mar. 31, 2023	$ 368,223	$ 712	$ 493,184		$ (1,018,034)	$ 55,986	$ 948,347