Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Narrative) (Details)

v3.8.0.1
Fair Value Measurements (Narrative) (Details) - USD ($)
3 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2017
Dec. 31, 2016
Fair Value Measurements [Abstract]      
Impairment loss $ 1,463,000 $ 1,617,389  
Transfers between levels   $ 0 $ 0