Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Stockholders' equity:
Common stock, par value	$ 0	$ 0
Common stock, authorized shares	40,000,000	40,000,000
Common stock, issued shares	21,583,032	20,783,032
Common stock, outstanding shares	21,583,032	20,783,032