Summary of Significant Accounting Principles (Details-1) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	$ 70,454	$ 44,738
Restricted cash	641	644
Receivable - margin account	550	1,657
Cash, cash equivalents, and restricted cash	71,645	47,039	$ 54,092	$ 25,814
MGE [Member]
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	57,003	4,103
Restricted cash	641	644
Receivable - margin account	550	1,657
Cash, cash equivalents, and restricted cash	$ 58,194	$ 6,404	$ 6,205	$ 5,529