Share-Based Compensation and Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2017

Restricted stock [Member]

Share-Based Compensation and Benefit Plans

Summary of activity of share-based compensation

	For the Three Months Ended   March 31,
	2017		2016
Compensation expense for shares issued under the ESPP	$	541	$	523
Income tax benefit from compensation expense related to shares issued under the ESPP	205		195
Compensation expense for restricted shares awarded	678		319
Income tax benefit from compensation expense related to restricted awards	$	257	$	119

Stock option [Member]

Share-Based Compensation and Benefit Plans

Summary of stock options

	Shares		Weighted-Average Exercise Price
Outstanding at December 31, 2016	2,800		$	104.90
Granted	177		266.53
Exercised	(284	)	44.69
Forfeited	(6	)	209.59
Outstanding at March 31, 2017	2,687		$	121.71
Exercisable at March 31, 2017	1,910		$	76.44

Black-Scholes option pricing model

	For the Three Months Ended   March 31,
	2017		2016
Risk free interest rate	2.09	%	1.59	%
Expected life	5.9 Years		5.9 Years
Expected volatility	22.3	%	22.4	%
Expected dividend yield	—	%	—	%

Summary of activity of share-based compensation

	For the Three Months Ended   March 31,
	2017		2016
Compensation expense for stock options awarded	$	4,209	$	4,336
Income tax benefit from compensation expense related to stock options	1,593		1,620
Weighted-average grant-date fair value of options awarded	$	70.34	$	66.27