Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Common stock, par value (per share)	$ 0.001	$ 0.001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	63,293,693	63,068,463
Common stock, shares outstanding	62,798,993	62,573,763
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