Stock-Based Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Stock Valuation Assumptions

The following assumptions were used in the valuation of stock options granted in 2019:

	2019
Expected volatility	26.7%
Risk-free interest rate range	2.47% to 2.70%
Expected life in years	6.6
Expected dividend yield	—

Stock Option Transactions for Employee Stock Option Plans

Stock option transactions for the second quarter and first six months of 2019 are summarized as follows:

	2019
	Second Quarter				Six Months
	Shares		Weighted Average Exercise Price		Shares		Weighted Average Exercise Price
Beginning balance	2,317,523		$	124.24	2,064,740		$	104.66
Granted	—		$	—	390,789		$	217.58
Exercised	(139,978	)	$	77.04	(260,761	)	$	80.62
Canceled	(6,702	)	$	187.44	(23,925	)	$	175.95
Ending balance	2,170,843		$	127.09	2,170,843		$	127.09
Options exercisable at end of period	1,410,369		$	79.43	1,410,369		$	79.43

Schedule of Restricted Stock Activity

The following table shows the restricted stock activity for the first six months of 2019:

	Shares		Weighted average fair value per share
Balance, December 30, 2018	74,220		$	108.05
Granted	17,522		$	200.00
Vested	(35,330	)	$	72.91
Balance, June 30, 2019	56,412		$	158.62