XML 68 R51.htm IDEA: XBRL DOCUMENT v3.19.1
Inventory (Details 1) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Reserve for Inventory    
Balance at Beginning of Year $ 4,274,000 $ (3,776,000)
Additions to Reserve (163,000) (503,000)
Deductions from Reserves 421,000 5,000
Balance at End of Year $ 4,016,000 $ 4,274,000