CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Stockholders' equity
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	10,640,735	8,997,704
Common stock, shares outstanding (in shares)	10,640,735	8,997,704