CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (loss) [Member]
Balance at Dec. 31, 2008	$ 112,108	$ 13	$ 80,318	$ 31,410	$ 367
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for employee purchase plan	326	0	326	0	0
Issuance of common stock for employee purchase plan (in shares)		59,365
Exercise of stock options	291	0	291	0	0
Exercise of stock options (in shares)		527,721
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards	(32)	0	(32)	0	0
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards (in shares)		43,042
Stock-based compensation expense	4,236	0	4,236	0	0
Tax benefit from exercises of stock-based payment awards	109	0	109	0	0
Change in accounting principle (see Note 1)	0	0	0	3,523	(3,523)
Components of other comprehensive loss:
Net loss	(17,679)	0	0	(17,679)	0
Other comprehensive income (loss)	1,494	0	0	0	1,494
Comprehensive loss	(16,185)	0	0	0	0
Balance at Dec. 31, 2009	100,853	13	85,248	17,254	(1,662)
Balance (in shares) at Dec. 31, 2009		13,436,163
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for employee purchase plan	306	0	306	0	0
Issuance of common stock for employee purchase plan (in shares)		43,859
Exercise of stock options	338	1	337	0	0
Exercise of stock options (in shares)		90,362
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards	(126)	0	(126)	0	0
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards (in shares)		59,329
Stock-based compensation expense	4,650	0	4,650	0	0
Tax benefit from exercises of stock-based payment awards	8	0	8	0	0
Components of other comprehensive loss:
Net loss	(10,518)	0	0	(10,518)	0
Other comprehensive income (loss)	(94)	0	0	0	(94)
Comprehensive loss	(10,612)	0	0	0	0
Balance at Dec. 31, 2010	95,417	14	90,423	6,736	(1,756)
Balance (in shares) at Dec. 31, 2010	13,629,713	13,629,713
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for employee purchase plan	276	0	276	0	0
Issuance of common stock for employee purchase plan (in shares)		45,161
Exercise of stock options	1,230	0	1,230	0	0
Exercise of stock options (in shares)		207,624
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards	(146)	0	(146)	0	0
Issuance of common stock in settlement of restricted stock units, net of shares withheld for employee taxes, and stock awards (in shares)		65,897
Stock-based compensation expense	3,907	0	3,907	0	0
Tax benefit from exercises of stock-based payment awards	29	0	29	0	0
Components of other comprehensive loss:
Net loss	(10,061)	0	0	(10,061)	0
Other comprehensive income (loss)	915	0	0	0	915
Comprehensive loss	(9,146)	0	0	0	0
Balance at Dec. 31, 2011	$ 91,567	$ 14	$ 95,719	$ (3,325)	$ (841)
Balance (in shares) at Dec. 31, 2011	13,948,395	13,948,395