
	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Employee stock-based compensation expense
Pre-tax	$	62	$	(52)	$	225	$	474
Post-tax (1)	49		(41)		178		374
Director stock-based compensation expense
Pre-tax	80		133		177		307
Post-tax (1)	63		105		140		243

We had approximately $2,453,000 of unrecognized stock compensation expense at June 30, 2021 related to non-vested stock-based compensation granted, which we expect to recognize over a weighted-average period of approximately 2.3 years. We had approximately $223,000 of unrecognized director stock-based compensation expense at June 30, 2021 related to non-vested director stock-based compensation granted, which we expect to recognize over a weighted-average period of approximately 0.8 years.

Stock-based compensation cost for restricted stock awards, restricted stock units and performance stock units is measured based on the closing fair market value of our common stock on the date of grant, which vest in equal installments over the requisite service period of typically three years. Restricted stock awards granted to non-employee directors vest over a one-year period. Each restricted stock unit and performance stock unit represents our obligation to deliver to the holder one share of common stock upon vesting.

Performance stock units vest based on the Company's return on average equity compared to a defined group of peer companies. On the grant date, we issue the target number of performance stock units. They are subject to forfeitures if performance goals are not met. The actual number of performance stock units earned can vary from zero to 150 percent of the target for the 2021, 2020, and 2019 awards.

We granted 208,812 and 288,026 shares of restricted common stock during the three and six month periods ended June 30, 2021, respectively, which had a weighted-average grant date fair value of $6.07 and $6.04 per share, respectively. We granted 346,078 and 347,254 shares of restricted common stock during the three and six month periods ended June 30, 2020, respectively, which had a weighted-average grant date fair value of $9.57 and $9.57 per share, respectively.

The following table presents certain information related to the activity of our non-vested common stock grants:


	Number of Restricted Shares	Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2020	259,006	$	10.06
Granted	288,026	6.04
Less: Forfeited	82,381	9.76
Less: Vested	80,072	10.00
Outstanding as of June 30, 2021	384,579	$	7.13

Stock option fair value was estimated on the grant date using the Black-Scholes-Merton formula. Stock options vest in equal installments over the requisite service period of typically three years. The following weighted-average assumptions were used to value the stock options granted:


	2021
Expected annual dividend yield	1.97	%
Expected volatility	42.10	%
Risk-free interest rate	2.20	%
Expected term	6

Expected annual dividend yield is based on the current quarterly dividend of $0.06 per share and the stock price on the grant date. The expected volatility is a historical volatility calculated based on the daily closing prices over a period equal to the expected term. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the grant date. Expected term takes into account the three-year graded vesting term and the 10-year contractual term of the option.

The following table presents certain information related to the activity of our non-vested stock option grants:


	Number of Stock Options	Weighted Average Exercise Prices		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2020	144,006	$	13.00	8.77	$	—
Granted	154,707	6.16		—	—
Less: Forfeited	21,777	10.49		—	—
Less: Expired	2,503	16.25		—	—
Less: Exercised	—	—		—	—
Outstanding as of June 30, 2021	274,433	$	9.31	9.12	$	—

Vested as of June 30, 2021(1)	111,324	$	15.10	8.00	$	—
Exercisable as of June 30, 2021	58,688	$	15.05	8.00	$	—