CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Total
Balances at Dec. 31, 2011	$ 5	$ 234,899	$ (922)	$ (1,698)	$ (160,949)	$ 71,335
Balances (in shares) at Dec. 31, 2011	48,368,476
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	0	0	0	0	(5,424)	(5,424)
Other comprehensive income (loss)		0	0	197	0	197
Stock-based compensation expense	0	4,525	0	0	0	4,525
Issuance of common stock upon exercise of stock options for cash	0	3,351	0	0	0	3,351
Issuance of common stock upon exercise of stock options for cash (in shares)	1,357,431
Issuance of common stock under employee stock purchase plan	0	179	0	0	0	179
Issuance of common stock under employee stock purchase plan (in shares)	84,082					84,082
Balances at Dec. 31, 2012	5	242,954	(922)	(1,501)	(166,373)	74,163
Balances (in shares) at Dec. 31, 2012	49,809,989
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	0	0	0	0	10,383	10,383
Other comprehensive income (loss)		0	0	(373)	0	(373)
Stock-based compensation expense	0	3,481	0	0	0	3,481
Issuance of common stock upon exercise of stock options for cash and releases of RSUs	0	8,435	0	0	0	8,435
Issuance of common stock upon exercise of stock options for cash and releases of RSUs (in shares)	4,392,786
Issuance of common stock under employee stock purchase plan	0	290	0	0	0	290
Issuance of common stock under employee stock purchase plan (in shares)	79,221					79,221
Repurchase of common stock	0	2,320	(4,114)	0	0	(1,794)
Repurchase of common stock (in shares)	(1,000,000)
Warrant-related charges	0	777	0	0	0	777
Utilized excess tax benefit (charge)	0	34	0	0	0	34
Balances at Dec. 31, 2013	5	258,291	(5,036)	(1,874)	(155,990)	95,396
Balances (in shares) at Dec. 31, 2013	53,281,996					53,281,996
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	0	0	0	0	(3,483)	(3,483)
Other comprehensive income (loss)	0	0	0	(154)	0	(154)
Stock-based compensation expense	0	2,874	0	0	0	2,874
Issuance of common stock upon exercise of stock options for cash and releases of RSUs	0	874	0	0	0	874
Issuance of common stock upon exercise of stock options for cash and releases of RSUs (in shares)	864,954
Issuance of common stock under employee stock purchase plan	0	222	0	0	0	222
Issuance of common stock under employee stock purchase plan (in shares)	117,533					117,533
Utilized excess tax benefit (charge)	0	(8)	0	0	0	(8)
Balances at Dec. 31, 2014	$ 5	$ 262,253	$ (5,036)	$ (2,028)	$ (159,473)	$ 95,721
Balances (in shares) at Dec. 31, 2014	54,264,483					54,264,483