Consolidated Statements of Changes in Stockholders' Equity and Accumulated Other Comprehensive Loss (USD $) In Thousands, unless otherwise specified	Total	Additional Paid-In Capital	Receivable for Common Stock Subscribed	Treasury Stock - Common Stock Voting	Accumulated Deficit	Accumulated Other Comprehensive Loss	Common Stock Voting	Common Stock Non-Voting
Balance at Dec. 31, 2008	$ 194,493	$ 305,508	$ (951)	$ (40,000)	$ (68,855)	$ (1,320)	$ 102	$ 9
Comprehensive income:
Net income	16,102				16,102
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(331)					(331)
Unrealized net gain on securities available-for-sale, net of tax	260					260
Total comprehensive income	16,031
Stock-based compensation	8,414	8,414
Exercise of stock options, warrants and grants of restricted stock, net of surrender on stock option exercises and withholding tax on stock vesting	242	240					2
Decrement in windfall from stock-based compensation	(266)	(266)
Repayment of promissory notes	238		238
Cash dividend on common stock and Series B Preferred Stock	(2,650)				(2,650)
Balance at Dec. 31, 2009	216,502	313,896	(713)	(40,000)	(55,403)	(1,391)	104	9
Comprehensive income:
Net income	31,428				31,428
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(564)					(564)
Unrealized net gain on securities available-for-sale, net of tax	304					304
Total comprehensive income	31,168
Stock-based compensation	8,969	8,969
Exercise of stock options, warrants and grants of restricted stock, net of surrender on stock option exercises and withholding tax on stock vesting	4,706	4,702					4
Tax benefit from the exercise of warrants in prior years	11,429	11,429
Excess tax benefits from stock-based compensation	1,619	1,619
Repayment of promissory notes	713		713
Purchase of treasury stock	(30,000)			(30,000)
Cash dividend on common stock and Series B Preferred Stock	(10,630)				(10,630)
Balance at Dec. 31, 2010	234,476	340,615		(70,000)	(34,605)	(1,651)	108	9
Comprehensive income:
Net income	47,704				47,704
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(634)					(634)
Unrealized net gain on securities available-for-sale, net of tax	403					403
Total comprehensive income	47,473
Stock-based compensation	6,859	6,859
Exercise of stock options, warrants and grants of restricted stock, net of surrender on stock option exercises and withholding tax on stock vesting	2,392	2,388					4
Conversion of Series B Preferred stock to common stock voting	30,315	(20,688)		51,002			1
Tax benefit from the exercise of warrants in prior years	4,237	4,237
Excess tax benefits from stock-based compensation	7,305	7,305
Purchase of treasury stock	(6,935)			(6,935)
Cash dividend on common stock	(13,683)				(13,683)
Balance at Dec. 31, 2011	$ 312,439	$ 340,716		$ (25,933)	$ (584)	$ (1,882)	$ 113	$ 9