Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Stockholders' equity:
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.004	$ 0.004
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	36,652,276	36,711,354
Common stock, shares outstanding	36,652,276	36,711,354