Share-Based Compensation and Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2020

Restricted stock [Member]

Share-Based Compensation and Benefit Plans

Summary of activity of share-based compensation and benefit plans

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
	2020		2019		2020		2019
Compensation expense for shares issued under the ESPP	$	717	$	622	$	2,060	$	1,831
Income tax benefit from compensation expense related to shares issued under the ESPP		180		155		517		456
Compensation expense for restricted shares awarded		392		351		1,094		1,038
Income tax benefit from compensation expense related to restricted awards	$	99	$	87	$	275	$	258

Stock option [Member]

Share-Based Compensation and Benefit Plans

Summary of stock options

	Shares	Weighted- Average
	(in thousands)	Exercise Price
Outstanding at December 31, 2019	1,635	$	218.10
Granted	162		389.99
Exercised	(251)		157.51
Forfeited or expired	(19)		298.31
Outstanding at September 30, 2020	1,527	$	245.27
Exercisable at September 30, 2020	1,006	$	199.31

Black-Scholes option pricing model

	September 30,
	2020		2019
Risk free interest rate	0.90	%	2.34	%
Expected life	6.1	Years	5.9	Years
Expected volatility	26.1	%	25.0	%
Expected dividend yield	—	%	—	%

Summary of activity of share-based compensation and benefit plans

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
	2020		2019		2020		2019
Compensation expense for stock options awarded	$	4,473	$	4,590	$	13,908	$	13,709
Income tax benefit from compensation expense related to stock options		1,123		1,143		3,492		3,415