General form of registration statement for all companies including face-amount certificate companies

BALANCE SHEETS (Unaudited) (Parenthetical)

v3.10.0.1
BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($)
Sep. 30, 2018
Dec. 31, 2017
Feb. 28, 2017
Statement of Financial Position [Abstract]      
Accounts receivable, allowance for doubtful accounts $ 77,067 $ 77,067 $ 18,046
Patents, accumulated amortization $ 229,693 $ 203,768 $ 180,137
Common stock, par value (in dollars per share) $ 0.01 $ 0.01 $ 0.01
Common stock, authorized 75,000,000 75,000,000 75,000,000
Common stock, issued 40,932,445 40,731,529 40,558,429
Common stock, outstanding 38,195,214 37,994,298 37,821,198
Treasury stock 2,737,231 2,737,231 2,737,231