Quarterly report pursuant to Section 13 or 15(d)

Fair value of financial instruments (Details 2)

v3.19.1
Fair value of financial instruments (Details 2) - Fair Value, Measurements, Nonrecurring [Member]
Dec. 31, 2018
USD ($)
Fair Value, Inputs, Level 1 [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value $ 0
Fair Value, Inputs, Level 1 [Member] | Convertible Notes Receivable [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 0
Fair Value, Inputs, Level 2 [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 0
Fair Value, Inputs, Level 2 [Member] | Convertible Notes Receivable [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 0
Fair Value, Inputs, Level 3 [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 904,317
Fair Value, Inputs, Level 3 [Member] | Convertible Notes Receivable [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 837,317
Investment in Warrants [Member] | Fair Value, Inputs, Level 1 [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 0
Investment in Warrants [Member] | Fair Value, Inputs, Level 2 [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value 0
Investment in Warrants [Member] | Fair Value, Inputs, Level 3 [Member]  
Investments, Fair Value Disclosure [Abstract]  
Assets, Fair Value $ 67,000