Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Change in Level 2 Assets (Details)

v3.21.1
Fair Value Measurements - Change in Level 2 Assets (Details) - USD ($)
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Proceeds from the sale of investment securities $ 11,637 $ 0
Eurosite Power, Inc.    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Equity, Number of Shares Sold 93,187  
Fair Value, Measurements, Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value, beginning $ 118,084 216,487
Sale of 93,187 shares (5,591)  
Unrealized loss included in net income for the six months ended June 30, 2019 37,497 (19,681)
Fair value, ending 149,990 196,806
Fair Value, Measurements, Recurring | Level 2 | Eurosite Power, Inc.    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value, ending $ 149,990 $ 196,806