Consolidated Balance Sheets Parentheticals - $ / shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Parentheticals - Balance Sheet [Abstract]
Preferred stock, par value (per share)	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
Common stock, par value (per share)	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized (shares)	200,000,000	200,000,000	200,000,000
Common stock, shares, issued (shares)	5,733,981	5,456,118	5,222,951
Common stock, shares outstanding (shares)	5,733,981	5,456,118	5,222,951