4. Accounting for Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

Valuation assumptions for stock-based compensation

	For Three Months Ended September 30, 2020			For Three Months Ended September 30, 2019		For Nine Months Ended September 30, 2020			For Nine Months Ended September 30, 2019
Weighted average grant date fair value		4.98			–	$	2.86		$	3.61
Weighted average assumptions used:
Expected dividend yield		0.0	%		–		0.0	%		0.0	%
Risk-free interest rate		0.23	%		–		0.42	%		2.19	%
Expected volatility		70.85	%		–		76.85	%		127.52	%
Expected life (in years)		5.0			–		6.13			5.0