Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Allowance for doubtful accounts	$ 187	$ 399
Common stock, par value (per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	75,000,000
Common stock, shares issued	67,006,796	63,866,392
Common stock, shares outstanding	66,909,398	63,866,392
Treasury stock, shares	97,398	0
Convertible Preferred Stock [Member]
Convertible preferred stock, par value (per share)	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	5,000,000	5,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0