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Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2021
Accounting Policies [Abstract]  
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions
 Expected VolatilityRisk-free Interest RateExpected TermDividend
Rate
December 31, 2021:    
Employees104%0.7%4%
Officers and non-employee directors90%1.0%6%
December 31, 2020:
Employees98%1.3%4%
Officers and non-employee directors85%1.4%7%
December 31, 2019:
Employees88%2.2%4%
Officers and non-employee directors77%2.6%8%