Consolidated Statements of Changes in Stockholders' Equity and Accumulated Other Comprehensive Loss (USD $) In Thousands, unless otherwise specified	Total	Common Stock Voting	Common Stock Non-Voting	Additional Paid-In Capital	Receivable for Common Stock Subscribed	Treasury Stock - Common Stock Voting	Accumulated Deficit	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2008	$ 194,493	$ 102	$ 9	$ 305,508	$ (951)	$ (40,000)	$ (68,855)	$ (1,320)
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 and grants of restricted stock, net of surrender on stock option exercises and withholding tax on stock vesting	242	2		240
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	104	9	313,896	(713)	(40,000)	(55,403)	(1,391)
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 and grants of restricted stock, net of surrender on stock option exercises and withholding tax on stock vesting	4,706	4		4,702
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	108	9	340,615	0	(70,000)	(34,605)	(1,651)
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 and grants of restricted stock, net of surrender on stock option exercises and withholding tax on stock vesting	2,392	4		2,388
Conversion of Series B Preferred stock to common stock voting	30,315	1		(20,688)		51,002
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	$ 113	$ 9	$ 340,716	$ 0	$ (25,933)	$ (584)	$ (1,882)