Summary of Significant Accounting Principles (Details-1) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	$ 40,239,000	$ 44,738,000
Restricted cash	467,000	644,000
Receivable - margin account	796,000	1,657,000
Cash, cash equivalents, and restricted cash	41,502,000	47,039,000	$ 19,794,000	$ 25,814,000
MGE [Member]
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	6,709,000	4,103,000
Restricted cash	467,000	644,000
Receivable - margin account	796,000	1,657,000
Cash, cash equivalents, and restricted cash	$ 7,972,000	$ 6,404,000	$ 5,664,000	$ 5,529,000