Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Treasury stock	Additional paid-in capital	Retained earnings (accumulated deficit)
Balance, Shares at Dec. 31, 2013		34,746,000
Balance at Dec. 31, 2013	$ 228,132	$ 35		$ 270,519	$ (42,422)
Exercise of stock options, Shares		648,000
Exercise of stock options	6,744	$ 1		6,743
Issuance of common stock under Employee Stock Purchase Plan, Shares		60,000
Issuance of common stock under Employee Stock Purchase Plan	2,100			2,100
Issuance of restricted stock units, net of shares withheld for employee taxes, Shares		25,000
Issuance of restricted stock units, net of shares withheld for employee taxes	(785)			(785)
Tax benefit from the exercise of stock	10,433			10,433
Stock-based compensation	14,558			14,558
Net income	18,242				18,242
Balance, Shares at Dec. 31, 2014		35,479,000
Balance at Dec. 31, 2014	279,424	$ 36		303,568	(24,180)
Exercise of stock options, Shares		465,000
Exercise of stock options	6,598			6,598
Issuance of common stock under Employee Stock Purchase Plan, Shares		54,000
Issuance of common stock under Employee Stock Purchase Plan	2,145			2,145
Issuance of restricted stock units, net of shares withheld for employee taxes, Shares		57,000
Issuance of restricted stock units, net of shares withheld for employee taxes	(949)			(949)
Tax benefit from the exercise of stock	$ 11,198			11,198
Treasury stock acquired (in shares)	(118,772)		(119,000)
Treasury stock acquired	$ (5,003)		$ (5,003)
Stock-based compensation	20,606			20,606
Net income	22,950				22,950
Balance, Shares at Dec. 31, 2015		36,055,000	(119,000)
Balance at Dec. 31, 2015	$ 336,969	$ 36	$ (5,003)	343,166	(1,230)
Exercise of stock options, Shares	926,000	926,000
Exercise of stock options	$ 16,070	$ 1		16,069
Issuance of common stock under Employee Stock Purchase Plan, Shares	52,727	53,000
Issuance of common stock under Employee Stock Purchase Plan	$ 2,194			2,194
Issuance of restricted stock units, net of shares withheld for employee taxes, Shares		213,000
Issuance of restricted stock units, net of shares withheld for employee taxes	(6,109)			(6,109)
Tax benefit from the exercise of stock	$ 17,871			17,871
Treasury stock acquired (in shares)	(226,170)		(226,000)
Treasury stock acquired	$ (9,371)		$ (9,371)
Stock-based compensation	30,268			30,268
Net income	20,205				20,205
Balance, Shares at Dec. 31, 2016		37,247,000	(345,000)
Balance at Dec. 31, 2016	$ 408,097	$ 37	$ (14,374)	$ 403,459	$ 18,975