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 (Loss)							6,113
Unrealized gain (loss) on short-term investments, net of tax						(2)
Foreign currency translation adjustments						(1,182)
Total comprehensive income (loss)	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, 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 (Loss)	23,911
Unrealized gain (loss) on short-term investments, net of tax	6
Foreign currency translation adjustments	(35,101)
Total comprehensive income (loss)	(11,184)
Balance, ending of period, shares at Sep. 30, 2022		31,664,000
Balance, ending of period at Sep. 30, 2022	344,305	$ 708	488,292		(995,606)	(73,448)	924,359		0
Balance, beginning of period, shares at Mar. 31, 2022		32,560,000
Balance, beginning of period at Mar. 31, 2022	414,172	$ 709	472,078	$ (9,802)	(946,102)	(39,537)	923,389	$ 9,802	3,635
Net Income (Loss)							5,317
Unrealized gain (loss) on short-term investments, net of tax						5
Foreign currency translation adjustments						(16,000)
Total comprehensive income (loss)	(10,678)
Repurchase of common stock	(21,673)		(116)		(21,557)
Repurchase of common stock, shares		(362,000)
Issuance of common stock pursuant to employee stock purchase plan	773		773
Issuance of common stock pursuant to employee stock purchase plan, shares		15,000
Issuance of restricted common stock pursuant to stock-based compensation plans		$ 1	(1)
Issuance of restricted common stock pursuant to stock-based compensation plans, shares		42,000
Cancellation of restricted common stock issued pursuant to stock-based compensation plans		$ (1)	1
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares		(60,000)
Stock-based compensation expense	6,536		6,536
Dividends	(8,473)						(8,473)
Write-off of noncontrolling interest	(3,635)								(3,635)
Balance, ending of period, shares at Jun. 30, 2022		32,195,000
Balance, ending of period at Jun. 30, 2022	377,022	$ 709	479,271		(967,659)	(55,532)	920,233
Net Income (Loss)	12,481						12,481
Unrealized gain (loss) on short-term investments, net of tax	3					3
Foreign currency translation adjustments	(17,919)					(17,919)
Total comprehensive income (loss)	(5,435)
Repurchase of common stock	(28,382)		(435)		(27,947)
Repurchase of common stock, shares		(495,000)
Issuance of common stock pursuant to employee stock purchase plan	794		794
Issuance of common stock pursuant to employee stock purchase plan, shares		16,000
Issuance of restricted common stock pursuant to stock-based compensation plans, shares		13,000
Cancellation of restricted common stock issued pursuant to stock-based compensation plans		$ (1)	1
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares		(65,000)
Stock-based compensation expense	8,661		8,661
Dividends	(8,355)						(8,355)
Balance, ending of period, shares at Sep. 30, 2022		31,664,000
Balance, ending of period at Sep. 30, 2022	$ 344,305	$ 708	488,292		(995,606)	(73,448)	924,359		$ 0
Balance, beginning of period, shares at Dec. 31, 2022	31,269,000	31,269,000
Balance, beginning of period at Dec. 31, 2022	$ 355,249	$ 708	495,189		(1,018,034)	(58,829)	936,215
Net Income (Loss)							20,928
Foreign currency translation adjustments						2,843
Total comprehensive income (loss)	23,771
Repurchase of common stock	(9,306)	$ (2)	(9,304)
Repurchase of common stock, shares		(166,000)
Issuance of common stock pursuant to employee stock purchase plan	893		893
Issuance of common stock pursuant to employee stock purchase plan, shares		19,000
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		574,000
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
Balance, ending of period at Mar. 31, 2023	$ 368,223	$ 712	493,184		(1,018,034)	(55,986)	948,347
Balance, beginning of period, shares at Dec. 31, 2022	31,269,000	31,269,000
Balance, beginning of period at Dec. 31, 2022	$ 355,249	$ 708	495,189		(1,018,034)	(58,829)	936,215
Net Income (Loss)	53,576
Unrealized gain (loss) on short-term investments, net of tax	0
Foreign currency translation adjustments	(1,943)
Total comprehensive income (loss)	$ 51,633
Balance, ending of period, shares at Sep. 30, 2023	29,726,000	29,726,000
Balance, ending of period at Sep. 30, 2023	$ 260,491	$ 713	483,063		(1,125,897)	(60,772)	963,384
Balance, beginning of period, shares at Mar. 31, 2023		31,678,000
Balance, beginning of period at Mar. 31, 2023	368,223	$ 712	493,184		(1,018,034)	(55,986)	948,347
Net Income (Loss)							13,954
Foreign currency translation adjustments						1,709
Total comprehensive income (loss)	15,663
Repurchase of common stock	(112)		(112)
Repurchase of common stock, shares		(2,000)
Issuance of common stock pursuant to employee stock purchase plan	771		771
Issuance of common stock pursuant to employee stock purchase plan, shares		18,000
Issuance of restricted common stock pursuant to stock-based compensation plans		$ 1	(1)
Issuance of restricted common stock pursuant to stock-based compensation plans, shares		64,000
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares		(7,000)
Stock-based compensation expense	7,644		7,644
Dividends	(8,878)						(8,878)
Balance, ending of period, shares at Jun. 30, 2023		31,751,000
Balance, ending of period at Jun. 30, 2023	383,311	$ 713	501,486		(1,018,034)	(54,277)	953,423
Net Income (Loss)	18,694						18,694
Unrealized gain (loss) on short-term investments, net of tax	0
Foreign currency translation adjustments	(6,495)					(6,495)
Total comprehensive income (loss)	12,199
Repurchase of common stock	(108,007)		(144)		(107,863)
Repurchase of common stock, shares		(1,994)
Issuance of common stock pursuant to employee stock purchase plan	877		877
Issuance of common stock pursuant to employee stock purchase plan, shares		20
Issuance of restricted common stock pursuant to stock-based compensation plans, shares		12
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares		(63)
Stock-based compensation expense	7,197		7,197
Purchase of capped call transactions (net of tax)	(26,353)		(26,353)
Dividends	$ (8,733)						(8,733)
Balance, ending of period, shares at Sep. 30, 2023	29,726,000	29,726,000
Balance, ending of period at Sep. 30, 2023	$ 260,491	$ 713	$ 483,063		$ (1,125,897)	$ (60,772)	$ 963,384