Share-Based Compensation and Benefit Plans (Tables)

6 Months Ended

Jun. 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 Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Compensation expense for shares issued under the ESPP	$	697	$	632	$	1,343	$	1,209
Income tax benefit from compensation expense related to shares issued under the ESPP		176		157		338		301
Compensation expense for restricted shares awarded		351		348		702		687
Income tax benefit from compensation expense related to restricted awards	$	88	$	86	$	177	$	171

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	149		384.75
Exercised	(121)		148.80
Forfeited or expired	(13)		293.46
Outstanding at June 30, 2020	1,650	$	237.64
Exercisable at June 30, 2020	1,107	$	193.01

Black-Scholes option pricing model

	June 30,
	2020		2019
Risk free interest rate	0.96	%	2.44	%
Expected life	6.2	Years	6.0	Years
Expected volatility	25.8	%	25.0	%
Expected dividend yield	—	%	—	%

Summary of activity of share-based compensation and benefit plans

	For the Three Months Ended				For the Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Compensation expense for stock options awarded	$	4,557	$	4,611	$	9,435	$	9,119
Income tax benefit from compensation expense related to stock options		1,148		1,146		2,377		2,267