Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (USD $) In Thousands	Total	Additional Paid-In Capital	Treasury Stock - Common Stock Voting	Retained Earnings (Deficit)	Accumulated Other Comprehensive Loss	Common Stock Voting	Common Stock Non-Voting
Balance at Dec. 31, 2011	$ 312,439	$ 340,716	$ (25,933)	$ (584)	$ (1,882)	$ 113	$ 9
Net income	26,122			26,122
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(280)				(280)
Unrealized net loss on securities available-for-sale, net of tax	(255)				(255)
Stock-based compensation	4,028	4,028
Exercise of stock options	5,428	5,425				3
Withholding tax payments on restricted stock vesting and stock option exercises	(20,003)	(20,003)
Excess tax benefits from stock-based compensation	13,681	13,681
Conversion of common stock non-voting to common stock voting		(15,878)	15,878			2	(2)
Repurchases of common stock	(71,143)	(52,908)	(18,228)				(7)
Cash dividend on common stock	(8,282)			(8,282)
Balance at Jun. 30, 2012	$ 261,735	$ 275,061	$ (28,283)	$ 17,256	$ (2,417)	$ 118	$ 0