Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2011	$ 14	$ 95,719	$ (3,325)	$ (841)	$ 91,567
Balance (in Shares) at Dec. 31, 2011	13,948,395
Issuance of common stock for employee purchase plan	0	289	0	0	289
Issuance of common stock for employee purchase plan (in Shares)	46,982
Exercise of stock options	0	1,480	0	0	1,480
Exercise of stock options (in Shares)	211,551				211,551
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards	0	(101)	0	0	(101)
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards (in Shares)	26,548
Stock-based compensation expense	0	3,159	0	0	3,159
Tax benefit from exercises of stock-based payment awards	0	6	0	0	6
Net loss	0	0	(6,548)	0	(6,548)
Net change in unrealized gain (loss) on available-for-sale investments	0	0	0	922	922
Balance at Dec. 31, 2012	14	100,552	(9,873)	81	90,774
Balance (in Shares) at Dec. 31, 2012	14,233,476
Issuance of common stock for employee purchase plan	0	362	0	0	362
Issuance of common stock for employee purchase plan (in Shares)	51,338
Exercise of stock options	1	5,048	0	0	5,049
Exercise of stock options (in Shares)	612,210				612,210
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards	0	(222)	0	0	(222)
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards (in Shares)	95,256
Repurchase of common stock	(1)	(10,030)	0		(10,031)
Repurchase of common stock (in Shares)	(1,060,447)
Stock-based compensation expense	0	3,110	0	0	3,110
Net loss	0	0	(4,747)	0	(4,747)
Net change in unrealized gain (loss) on available-for-sale investments	0	0	0	(30)	(30)
Balance at Dec. 31, 2013	14	98,820	(14,620)	51	84,265
Balance (in Shares) at Dec. 31, 2013	13,931,833				13,931,833
Issuance of common stock for employee purchase plan	0	451	0	0	451
Issuance of common stock for employee purchase plan (in Shares)	52,759
Exercise of stock options	0	3,307	0	0	3,307
Exercise of stock options (in Shares)	396,970				396,970
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards	0	(156)	0	0	(156)
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards (in Shares)	65,388
Stock-based compensation expense	0	3,299	0	0	3,299
Net loss	0	0	(10,612)	0	(10,612)
Net change in unrealized gain (loss) on available-for-sale investments	0	0	0	(46)	(46)
Balance at Dec. 31, 2014	$ 14	$ 105,721	$ (25,232)	$ 5	$ 80,508
Balance (in Shares) at Dec. 31, 2014	14,446,950				14,446,950