In April 2007, the Board approved the 2007 Stock Option and Incentive Plan (the “2007 Plan”), which was approved by the stockholders of the Company and became effective upon the consummation of the Company’s IPO in May 2007. The 2007 Plan allowed the Company to grant ISOs, NSOs, stock appreciation rights, deferred stock awards, restricted stock units and other awards. Under the 2007 Plan, stock options could not be granted at less than fair market value on the date of grant, and grants generally vested over a three- to four-year period. Stock options granted under the 2007 Plan expire no later than ten years after the grant date. Additionally, beginning with awards made in August 2015, the Company had the option to direct a net issuance of shares for satisfaction of tax liability with respect to vesting of awards and delivery of shares. Prior to August 2015, this choice of settlement method was solely at the discretion of the award recipient. The 2007 Plan expired in May 2017.

No new awards may be granted under the 2007 Plan; however, the shares of common stock remaining in the 2007 Plan are available for issuance in connection with previously awarded grants under the 2007 Plan. There are 77,500 shares of common stock that remain subject to outstanding stock grants under the 2007 Plan as of March 31, 2020.

In March 2017, the Board approved the 2017 Stock Option and Incentive Plan (the “2017 Plan”), which was approved by the stockholders of the Company at the 2017 Annual Meeting and became effective June 16, 2017. The 2017 Plan replaces the Company’s 2007 Plan. On that date, 3,000,000 shares of Common Stock were reserved for issuance under the 2017 Plan and, generally, shares that are forfeited or canceled from awards under the 2017 Plan also will be available for future awards. Under the 2017 Plan, the Company may grant restricted stock and restricted stock units, non-qualified stock options, stock appreciation rights, performance awards, and other stock-based and cash-based awards. Grants generally vest in equal tranches over a three-year period. Stock options granted under the 2017 Plan expire no later than ten years after the grant date. Shares of stock issued pursuant to restricted stock awards are restricted in that they are not transferable until they vest. Stock underlying awards of restricted stock units are not issued until the units vest. Non-qualified stock options cannot be exercised until they vest. Under the 2017 Plan, all stock options and stock appreciation rights must be granted with an exercise price that is at least equal to the fair market value of the stock on the date of grant. The 2017 Plan broadly prohibits the repricing of options and stock appreciation rights without stockholder approval and requires that no dividends or dividend equivalents be paid with respect to options or stock appreciation rights. The 2017 Plan further provides that, in the event any dividends or dividend equivalents are declared with respect to restricted stock, restricted stock units, other stock-based awards and performance awards (referred to as “full-value awards”), they would be subject to the same vesting and forfeiture provisions as the underlying award. There is a total of 1,363,630 shares of common stock that remain subject to outstanding stock grants under the 2017 Plan as of March 31, 2020.

The Company uses the Black-Scholes option pricing model to calculate the grant date fair value of an award.

The expected volatility of options granted has been determined using a weighted average of the historical volatility of the Company’s stock for a period equal to the expected life of the option. The expected life of options has been determined utilizing the “simplified” method. The risk-free interest rate is based on a zero coupon U.S. treasury instrument whose term is consistent with the expected life of the stock options. The Company has not paid and does not anticipate paying cash dividends on its shares of common stock; therefore, the expected dividend yield is assumed to be zero. The Company applied an estimated annual forfeiture rate based on historical averages in determining the expense recorded in each period.

A summary of the stock option activity under the Company’s plans for the three months ended March 31, 2020 is presented below:

Year-to-Date Activity	Options Outstanding		Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term in Years		Aggregate Intrinsic Value
Options outstanding at December 31, 2019		140,000	$	13.14
Granted
Exercised
Forfeited
Cancelled
Options outstanding at March 31, 2020		140,000	$	13.14		5.68	$	1,208
Options exercisable at March 31, 2020		117,500	$	11.76		5.00	$	1,196
Options vested or expected to vest at March 31, 2020		139,548	$	13.11		5.67	$	1,208

There were no options exercised during the three months ended March 31, 2020. The total intrinsic value of options exercised (i.e. the difference between the market price at exercise and the price paid by the employee to exercise the options) was $138 thousand during the three months ended March 31, 2019. The total amount of cash received from exercise of these options was approximately $23 thousand during the three months ended, March 31, 2019.

Restricted stock units are valued at the market price of a share of the Company’s common stock on the date of the grant. A summary of the restricted stock unit activity under the Company’s plans for the three months ended March 31, 2020 is presented below:

Year-to-Date Activity	Shares			Weighted- Average Grant Date Fair Value Per Share		Aggregate Intrinsic Value
Nonvested outstanding at December 31, 2019		1,301,130		$	21.82	$	—
Granted		95,688		$	21.10		—
Vested		(95,688	)	$	21.10		—
Forfeited		—		$	0.00		—
Nonvested outstanding at March 31, 2020		1,301,130		$	21.82	$	26,816

There were 95,688 restricted stock units with a total grant-date fair value of $2.0 million that vested during the three months ended March 31, 2020. There were 42,604 restricted stock units with a total grant-date fair value of $0.7 million that vested during the that vested during the three months ended March 31, 2019.

As of, March 31, 2020 there was $20.5 million of total unrecognized compensation expense related to stock options and restricted stock units, which is expected to be recognized over a weighted average period of 1.7 years.