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Derivative Instruments and Hedging Activities Fair Value Assumptions of Warrants (Details)
3 Months Ended 12 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]    
Expected term (years) 1 year 6 months 1 year 9 months
Estimated volatility 96.05% 81.45%
Risk-free interest rate 0.54% 1.69%
Expected dividend yield 0.00% 0.00%