Summary of Significant Accounting Policies - (Tables)

3 Months Ended

Mar. 31, 2020

Accounting Policies [Abstract]

Schedule of weighted-average assumptions used to estimate grant date fair value of stock options

The weighted-average assumptions used to estimate grant date fair value of stock options using the Black-Scholes option pricing model were as follows for the three month periods ended March 31, 2020 and 2019:

	Three Months Ended March 31,
	2020	2019
Expected common stock price volatility	115%	86%
Risk-free interest rate	0.87%-1.34%	2.50%-2.54%
Expected term of options (years)	4.7	6.2
Expected dividend yield	—	—