At September 30, 2020, approximately 1.2 million shares are available for future use under our long-term incentive plan.

Share-based compensation activity during the nine months ended September 30, 2020 included the following:

(Shares in thousands)	Granted		Vested		Forfeited
Performance Share Awards (PSAs)		125,001		—		4,286
Restricted Stock Units (RSUs)		68,263		28,671		1,429

Approximately 0.1 million shares of common stock were issued during the nine months ended September 30, 2020 as a result of PSA and RSU vesting during 2019 and 2020.

The following table details equity-based compensation expense and the related income tax benefit:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2020		2019		2020		2019
Equity-based compensation expense:
Performance share awards	$	1,315	$	1,186	$	3,716	$	3,417
Restricted stock units		729		705		2,155		1,892
Deferred compensation stock equivalent units expense		19		22		57		53
Total equity-based compensation expense	$	2,063	$	1,913	$	5,928	$	5,362

Total tax benefit recognized for equity-based expense	$	97	$	79	$	273	$	234

PSAs granted under the stock incentive plans have a three-year performance period and shares are issued at the end of the period if the performance measures are met. The performance measures are based on the percentile ranking of our total shareholder return relative to the total shareholder return performance of both a selected peer group of companies and a larger group of indexed companies over the three-year performance period. The number of shares actually issued, as a percentage of the amount subject to the PSA, could range from 0% to 200%. PSAs granted under our stock incentive plans do not have voting rights unless and until shares are issued upon settlement. If shares are issued at the end of the three-year performance measurement period, the recipients will receive dividend equivalents in the form of additional shares at the time of payment equal to the dividends that would have been paid on the shares earned had the recipients owned the shares during the three-year period. Therefore, the shares are not considered participating securities. The fair value of performance shares granted in 2020 was $45.04 per share.

The following table presents the key inputs used in the Monte Carlo simulation to calculate the fair value of the performance share awards in 2020:

Stock price as of valuation date	$	42.16
Risk-free rate		1.42	%
Expected volatility		25.74	%
Expected dividend yield (assuming full reinvestment)		—
Expected term (years)		3.00

RSU awards accrue dividend equivalents based on dividends paid during the RSU vesting period. The dividend equivalents will be converted into additional RSUs that will vest in the same manner as the underlying RSUs to which they relate. Therefore, the shares are not considered participating securities. The terms of the awards state that the RSUs will vest in a given time period of one to three years and the terms of certain awards follow a vesting schedule within the given time period. The fair value of RSUs granted equaled our common share price on the date of grant factoring in any required post-vesting holding periods. The weighted average fair value of all RSUs granted during the nine months ended September 30, 2020 was $38.77 per share.