Share-Based Compensation and Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2019

Restricted stock [Member]

Share-Based Compensation and Benefit Plans

Summary of activity of share-based compensation

	For the Three Months Ended   March 31,
	2019		2018
Compensation expense for shares issued under the ESPP	$	577	$	543
Income tax benefit from compensation expense related to shares issued under the ESPP	142		136
Compensation expense for restricted shares awarded	339		341
Income tax benefit from compensation expense related to restricted awards	$	84	$	86

Stock option [Member]

Share-Based Compensation and Benefit Plans

Summary of stock options

	Shares		Weighted-Average Exercise Price
Outstanding at December 31, 2018	1,860		$	178.57
Granted	136		355.99
Exercised	(133	)	89.66
Forfeited	(10	)	250.31
Outstanding at March 31, 2019	1,853		$	197.62
Exercisable at March 31, 2019	1,215		$	154.27

Black-Scholes option pricing model

	For the Three Months Ended   March 31,
	2019		2018
Risk free interest rate	2.50	%	2.58	%
Expected life	6.2 Years		6.3 Years
Expected volatility	25.0	%	23.7	%
Expected dividend yield	—	%	—	%

Summary of activity of share-based compensation

	For the Three Months Ended   March 31,
	2019		2018
Compensation expense for stock options awarded	$	4,508	$	4,292
Income tax benefit from compensation expense related to stock options	1,112		1,078
Weighted-average grant-date fair value of options awarded	$	108.74	$	75.42