Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands	Total	Common Stock Voting [Member]	Additional Paid-in Capital [Member]	Treasury Stock - Common Stock Voting [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2014	$ 334,208	$ 120	$ 307,059	$ (70,247)	$ 101,813	$ (4,537)
Net income	24,593				24,593
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(49)					(49)
Unrealized net gain on securities available-for-sale, net of tax	63					63
Stock-based compensation	3,042		3,042
Exercise of stock options	692		692
Withholding tax payments on restricted stock vesting and stock option exercises	(4,148)		(4,148)
Excess tax benefits from stock-based compensation	2,671		2,671
Repurchases of common stock	(8,939)			(8,939)
Cash dividend on common stock	(7,463)				(7,463)
Ending Balance at Mar. 31, 2015	$ 344,670	$ 120	$ 309,316	$ (79,186)	$ 118,943	$ (4,523)