Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Deferred Compensation Arrangements [Abstract]

Share-based Payment Arrangement, Expensed and Capitalized, Amount

The following is a summary of stock-based compensation expense, net of any forfeitures, included in “General and administrative expenses” in the Condensed Consolidated Statements of Income ($ in thousands):

	Three Months Ended
	March 31,
	2021		2020
Non-cash stock-based compensation expense	$	5,446	$	1,845

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair value of each grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions:

	2021	2020
Dividend yield	6.7%	5.1%
Expected volatility	48.1%	16.8%
Expected lives	2.9 years	2.9 years
Risk-free interest rate	0.33%	1.31%

Schedule of Stock Option Activity

The following table summarizes our outstanding stock options:

			Weighted Average
	Number	Weighted Average	Remaining
	of Shares	Exercise Price	Contractual Life (Years)
Options outstanding January 1, 2020	1,004,014	$74.35
Options granted	584,500	$90.79
Options exercised	(512,509)	$72.98
Options forfeited	(8,000)	$88.08
Options outstanding, March 31, 2020	1,068,005	$83.90
Exercisable at March 31, 2020	600,327	$81.22
Options outstanding January 1, 2021	1,033,838	$83.54
Options granted	652,000	$69.20
Options exercised	(20,000)	$60.52
Options outstanding, March 31, 2021	1,665,838	$78.20	3.88
Exercisable at March 31, 2021	1,180,824	$79.31	3.58