Share-Based Compensation and Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2019

Share-Based Compensation and Benefit Plans

Summary of shares authorized and available for future issuance under compensation and benefit plans

	December 31, 2019
	Total Shares Authorized for	Shares Available for Future
Plans	Issuance under the Plans	Issuance under the Plans
Incentive Plans	34,650	5,749
Employee Stock Purchase Plan	4,250	551
Profit Sharing and Savings Plan	4,200	349

Restricted stock [Member]

Share-Based Compensation and Benefit Plans

Summary of activity of share-based compensation and benefit plans

	For the Year Ended
	December 31,
	2019		2018		2017
Compensation expense for restricted shares awarded	$	1,387	$	1,370	$	1,628
Income tax benefit from compensation expense related to restricted shares	$	341	$	340	$	621
Total fair value of restricted shares at vest date	$	1,633	$	1,230	$	1,202
Shares awarded under the plans		4		5		4
Weighted-average grant-date fair value of shares awarded under the plans	$	355.91	$	263.89	$	253.78

Employee stock purchase plan [Member]

Share-Based Compensation and Benefit Plans

Summary of ESPP plan activity

	For the Year Ended
	December 31,
	2019		2018		2017
Compensation expense for shares issued under the ESPP	$	2,490	$	2,285	$	2,212
Income tax benefit from compensation expense related to shares issued under the ESPP	$	612	$	566	$	844
Shares issued under the ESPP		43		53		64
Weighted-average price of shares issued under the ESPP	$	329.69	$	245.26	$	196.72

Employee [Member] | Restricted stock [Member]

Share-Based Compensation and Benefit Plans

Summary of restricted stock

		Weighted-Average Grant-Date
	Shares	Fair Value
Non-vested at December 31, 2018	4	$	260.42
Granted during the period	2		344.66
Vested during the period (1)	(2)		259.43
Forfeited during the period	—		—
Non-vested at December 31, 2019	4	$	301.40

Director [Member] | Restricted stock [Member]

Share-Based Compensation and Benefit Plans

Summary of restricted stock

		Weighted-Average Grant-Date
	Shares	Fair Value
Non-vested at December 31, 2018	5	$	261.07
Granted during the period	2		367.77
Vested during the period	(3)		280.41
Forfeited during the period	—		—
Non-vested at December 31, 2019	4	$	312.96

Stock option [Member]

Share-Based Compensation and Benefit Plans

Black-Scholes option pricing model

	December 31,
	2019		2018		2017
Risk free interest rate	2.26	%	2.63	%	1.98	%
Expected life	5.7	Years	5.9	Years	5.4	Years
Expected volatility	25.1	%	24.0	%	22.4	%
Expected dividend yield	—	%	—	%	—	%

Summary of activity of share-based compensation and benefit plans

	For the Year Ended
	December 31,
	2019		2018		2017
Compensation expense for stock options awarded (in thousands)	$	18,044	$	16,521	$	15,561
Income tax benefit from compensation expense related to stock options (in thousands)		4,436		4,093		5,934
Total intrinsic value of stock options exercised (in thousands)		117,489		156,327		135,533
Cash received from exercise of stock options (in thousands)		46,106		61,403		33,229
Weighted-average grant-date fair value of options awarded	$	105.37	$	76.57	$	62.79
Weighted-average remaining contractual life of exercisable options (in years)		4.6		4.4		3.8

Stock option [Member] | Employee stock option [Member]

Share-Based Compensation and Benefit Plans

Summary of stock options

				Average		Aggregate
	Shares	Weighted- Average		Remaining		Intrinsic Value
	(in thousands)	Exercise Price		Contractual Terms		(in thousands)
Outstanding at December 31, 2018	1,860	$	178.57
Granted	214		370.63
Exercised	(406)		113.66
Forfeited or expired	(33)		263.15
Outstanding at December 31, 2019	1,635	$	218.10	5.9	Years	$	360,003
Vested or expected to vest at December 31, 2019	1,598	$	215.97	5.9	Years	$	355,172
Exercisable at December 31, 2019	1,033	$	170.77	4.6	Years	$	276,414