CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Balance at Dec. 31, 2011	$ 208,756	$ 754	$ 129,324	$ 77,029	$ 1,649
Balance (in shares) at Dec. 31, 2011		75,424
Repurchase of common stock (in shares)		(370)
Repurchase of common stock	(5,206)	(4)	(5,202)
Exercise of Common Stock Warrants (in shares)		5
Exercise of common stock warrants	0	0	0	0	0
Issuance of common stock for share-based compensation plans (in shares)		762
Issuance of common stock for share-based compensation plans	(3,865)	8	(3,873)
Issuance of stock under Employee Stock Purchase Plan (in shares)		44
Issuance of stock under Employee Stock Purchase Plan	603		603
Issuance of stock awards (in shares)		25
Issuance of stock awards	0	0	0	0	0
Stock-based compensation expense	11,506		11,506
Tax benefit from exercise or vesting of equity awards, net of deferred tax asset deficiencies	5,839		5,839
Cash dividends declared	(4,548)			(4,548)
Other comprehensive income	1,526				1,526
Net income	21,868			21,868
Balance at Dec. 31, 2012	236,479	758	138,197	94,349	3,175
Balance (in shares) at Dec. 31, 2012		75,890
Repurchase of common stock (in shares)		(780)
Repurchase of common stock	(12,524)	(8)	(12,516)
Issuance of common stock for share-based compensation plans (in shares)		1,149
Issuance of common stock for share-based compensation plans	(5,680)	14	(5,694)
Issuance of stock under Employee Stock Purchase Plan (in shares)		38
Issuance of stock under Employee Stock Purchase Plan	545		545
Issuance of stock awards (in shares)		27
Issuance of stock awards	0	0	0	0	0
Stock-based compensation expense	12,869		12,869
Tax benefit from exercise or vesting of equity awards, net of deferred tax asset deficiencies	6,164		6,164
Cash dividends declared	(4,566)			(4,566)
Other comprehensive income	458				458
Net income	38,043			38,043
Balance at Dec. 31, 2013	271,788	764	139,565	127,826	3,633
Balance (in shares) at Dec. 31, 2013		76,324
Repurchase of common stock (in shares)		(770)
Repurchase of common stock	(15,559)	(8)	(15,551)
Issuance of common stock for share-based compensation plans (in shares)		742
Issuance of common stock for share-based compensation plans	(5,695)	8	(5,703)
Issuance of stock under Employee Stock Purchase Plan (in shares)		32
Issuance of stock under Employee Stock Purchase Plan	568		568
Issuance of stock awards (in shares)		29
Issuance of stock awards	0	0	0	0	0
Stock-based compensation expense	19,205		19,205
Tax benefit from exercise or vesting of equity awards, net of deferred tax asset deficiencies	3,411		3,411
Cash dividends declared	(8,023)			(8,023)
Other comprehensive income	(4,245)				(4,245)
Net income	33,255			33,255
Balance at Dec. 31, 2014	$ 294,705	$ 764	$ 141,495	$ 153,058	$ (612)
Balance (in shares) at Dec. 31, 2014		76,357