Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 655	$ 533
Allowance for doubtful long-term receivables	3,431	3,431
Discount on senior secured convertible notes	$ 1,276	$ 1,533
Convertible preferred stock, par value	$ 0.00001	$ 0.00001
Convertible preferred stock, shares authorized	10,000	10,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	65,000	65,000
Common stock, shares issued	23,227	23,038
Common stock, shares outstanding	23,227	23,038