As of December 31, 2021, the Company has an Omnibus Incentive Plan under which 1,000,000 shares are reserved for restricted stock, performance shares and stock options grants for employees, as well as stock grants for directors. The plan was approved in 2021 and replaced all prior stock-based plans except for shares and options previously issued under those plans. As of December 31, 2021 there were 994,119 shares of the Company’s Common Stock available for grant under the 2021 Omnibus Incentive Plan. The Company recognizes the cost of stock-based awards in net earnings for all of its stock-based compensation plans on a straight-line basis over the service period of the awards. The following sections describe the four types of grants in more detail.

The Company estimates the fair value of its option awards using the Black-Scholes option-pricing formula, and records compensation expense for stock options ratably over the stock option grant’s vesting period. Stock option compensation expense recognized by the Company for the year ended December 31, 2021 and 2020 was $0.4 million and $0.3 million in 2019. No new stock options were granted in 2021.

The following table summarizes the transactions of the Company’s stock option plans for the three-year period ended December 31, 2021:

	Number of shares			Weighted- average exercise price
Options outstanding - December 31, 2018		376,900		$	28.95
Options granted		34,926			59.44
Options exercised		(66,969	)		29.29
Options forfeited		(7,525	)		38.81
Options outstanding - December 31, 2019		337,332		$	31.82
Options granted		41,807		$	62.76
Options exercised		(55,716	)		18.99
Options forfeited		(7,229	)		50.19
Options outstanding - December 31, 2020		316,194		$	37.75
Options exercised		(88,932	)	$	22.89
Options outstanding - December 31, 2021		227,262		$	43.56
Exercisable options —
December 31, 2019		271,252		$	27.17
December 31, 2020		235,829			30.82
December 31, 2021		170,484			38.31

The following assumptions were used for valuing options granted in the year ended December 31, 2020:

Per share fair value of options granted during the period	$	17.49
Risk-free interest rate		0.64	%
Dividend yield		1.05	%
Volatility factor		30.0	%
Weighted-average expected life in years		7.0

The weighted-average contractual life remaining for options outstanding as of December 31, 2021 was 4.7 years. The expected life is based on historical exercise behavior and the projected exercise of unexercised stock options. The risk-free interest rate is based on the U.S. Treasury yield curve in effect on the date of grant for the respective expected life of the option. The expected dividend yield is based on the expected annual dividends divided by the grant date market value of the Company’s Common Stock. The expected volatility is based on the historical volatility of the Company’s Common Stock.

The following table summarizes the aggregate intrinsic value related to options exercised, outstanding and exercisable as of and for the years ended December 31:

	2021		2020		2019
	(In thousands)
Exercised	$	7,085	$	3,054	$	1,870
Outstanding		14,316		17,805		11,170
Exercisable		11,635		14,913		10,243

As of December 31, 2021, the unrecognized compensation cost related to stock options was approximately $0.7 million, which will be recognized over a weighted average period of 2.6 years.

Non-employee directors receive an annual award of $60,000 worth of restricted shares of the Company’s Common Stock under the shareholder-approved 2021 Omnibus Incentive Plan. The Company values stock grants for directors at the closing price of the Company’s stock on the day the grant was awarded. The Company records compensation expense for this plan ratably over the annual service period beginning May 1. Director stock compensation expense recognized by the Company for the years ended December 31, 2021 was $0.3 million compared to $0.4 million in 2020 and $0.3 million in 2019. As of December 31, 2021, the unrecognized compensation cost related to the director stock award that is expected to be recognized over the remaining four months is estimated to be approximately $0.1 million.

The Company periodically issues nonvested shares of the Company's Common Stock to certain eligible employees. The Company values restricted stock on the closing price of the Company's stock on the day the grant was awarded. The Company records compensation expense for this plan ratably over the vesting periods. Restricted stock compensation expense recognized by the Company for the year ended December 31, 2021 was $1.4 million compared to $1.0 million in 2020 and $0.9 million in 2019.

The fair value of nonvested shares is determined based on the market price of the shares on the grant date.

	Shares			Fair value per share
Nonvested at December 31, 2018		72,802		$	42.58
Granted		16,034			59.42
Vested		(19,227	)		30.08
Forfeited		(5,129	)		41.31
Nonvested at December 31, 2019		64,480		$	48.21
Granted		20,758			64.19
Vested		(25,044	)		39.87
Forfeited		(2,645	)		54.35
Nonvested at December 31, 2020		57,549		$	57.33
Granted		17,430			99.90
Vested		(16,528	)		49.31
Forfeited		(1,384	)		58.68
Nonvested at December 31, 2021		57,067		$	72.62

As of December 31, 2021, there was $2.0 million of unrecognized compensation cost related to nonvested restricted stock that is expected to be recognized over a weighted average period of 1.8 years.

Beginning in 2021, the Company periodically issues performance share units to certain eligible employees. Recipients of performance share grants are eligible to receive shares of our common stock depending upon the level of our total adjusted free cash flow conversion and adjusted return on invested capital (ROIC) as measured over a three-year performance period. The number of shares earned for awards granted in fiscal 2021 will range from 50% to 200% of the targeted number of performance shares for the three-year performance period ending December 31, 2023 and will vest, to the extent earned, in the fiscal quarter following the end of the applicable three-year performance period. Performance share compensation expense recognized by the Company for the year ended December 31, 2021 was $0.6 million.

A summary of performance share activity for the year ended December 31, 2021 is as follows:

	Performance Shares		Weighted Average Grant Date Fair Value
Nonvested at December 31, 2020		—	$	—
Granted		14,748		100.37
Adjustment for expected performance results		7,374		100.37
Nonvested at December 31, 2021		22,122	$	100.37

As of December 31, 2021 there was $1.6 million of unrecognized compensation cost related to nonvested performance share units that is expected to be realized over a weighted average period of 2.2 years.