Note 20 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Restricted Stock Unit Activity

The following table summarizes information about restricted stock unit activity for the nine months ended September 30, 2020:

	Number of Restricted Stock Units		Weighted-Average Grant Date Fair Values
Outstanding on December 31, 2019		721,801	$	3.25
Granted		351,909	$	2.91
Vested		692,751	$	3.05
Outstanding on September 30, 2020		380,959	$	3.31

Stock Option Activity

The following table summarizes information about stock option activity for the nine months ended September 30, 2020:

	Shares Under Option		WeightedAverage Exercise Price Per Share		WeightedAverage Remaining Contractual Life (Years)	Aggregate Intrinsic Value ($ millions)
Outstanding on December 31, 2019		6,843,079	$	10.96
Granted		2,917,464	$	5.86
Exercised		2,019,187	$	14.51
Forfeited		27,075	$	12.50
Outstanding on September 30, 2020		7,714,281	$	8.09	5.09	$	23
Exercisable on September 30, 2020		6,858,431	$	8.49	4.91	$	19
Expected to vest September 30, 2020		855,850	$	4.91	6.52	$	4

Valuation of Option Grants

The following inputs were used in the Black-Scholes valuation of option grants issued in each period:

	Nine Months Ended
	September 30,
	2020		2019
Weighted-average fair value of options granted	$	1.50	$	1.73
Risk-free interest rate	2.43%		2.47%
Expected option lives	3.7 years		4.5 years
Expected volatility	98%		90%
Expected dividend yield	0.00%		0.00%

The following inputs were used in the lattice-based valuation of the July 27, 2020 option grants:

	July 27, 2020
	Option Awards
Weighted-average fair value of options granted	$	6.57
Range of risk-free interest rates	0.11% -0.30%
Weighted-average term	5.57 years
Weighted-average volatility	98%
Weighted-average expected dividend yield	0.00%