Consolidated Statement of Changes in Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Balance at beginning of period at Dec. 31, 2013	$ 106	$ 400,716	$ (196)	$ (65,156)	$ 335,470
Balance at beginning of period (in shares) at Dec. 31, 2013	106,314,909				106,314,909
Increase (Decrease) in Stockholders' Deficit
Issuance of common stock in connection with exercises of stock options	1	1,035			1,036
Issuance of common stock in connection with exercises of stock options (in shares)	385,313
Issuance of common stock in connection with vesting of restricted stock units, net of withholdings		(457)			(457)
Issuance of common stock in connection with vesting of restricted stock units, net of withholdings (in shares)	137,301
Stock-based compensation expense		3,772			3,772
Net loss				(12,947)	(12,947)
Intra-entity foreign currency transaction adjustments			(30)		(30)
Foreign currency translation adjustments			1		1
Balance at end of period at Mar. 31, 2014	$ 107	$ 405,066	$ (225)	$ (78,103)	$ 326,845
Balance at end of period (in shares) at Mar. 31, 2014	106,837,523				106,837,523