Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts	$ 472	$ 161
Common stock, par value (per share)	$ 0.001	$ 0.001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	63,068,463	58,577,484
Common stock, shares outstanding	62,573,763	58,082,784
Treasury stock, shares	494,700	494,700
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