Unaudited Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Class of stock information
Common stock, par value per share (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	94,098,515	93,569,642
Common stock, shares outstanding	94,098,515	93,569,642