Stock Option Plans (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Stock Options Issued

The following table summarizes the assumptions used in the valuation of the 2020 and 2019 option grants. During the six months ended June 30, 2020, stock option expense totaling $700,700 was included in general and administrative expense in the Consolidated Statements of Operations. As of June 30, 2020, the estimated future expense related to unvested stock options was $2.2 million.

	Directors						Officers
Grant date	May 3, 2019			April 24, 2020			May 3, 2019			April 24, 2020
Exercise price	$	55.71		$	50.00		$	55.71		$	50.00
Volatility	0.236			0.258			0.206			0.240
Expected life (years)	5.0			5.0			7.0			7.0
Assumed yield	3.75		%	3.80		%	3.80		%	3.85		%
Risk-free rate	2.33		%	0.36		%	2.43		%	0.51		%

Summary of Option Activity

The table below summarizes the option activity for the six months ended  June 30, 2020:

	Number of Shares		Weighted Average Exercise Price per share		Aggregate Intrinsic Value
Outstanding at January 1	1,309,614		$	53.38	$	2,528,463
Granted	238,000		50.00		—
Exercised	(10,749	)	49.19		85,268
Expired/Forfeited	(21,250	)	53.96		—
Outstanding at June 30	1,515,615		52.87		—
Exercisable at June 30	978,240		53.03		—