Share-based Arrangements (Tables)

9 Months Ended

Sep. 27, 2019

Stock option activity was as follows:



	For the Three Months Ended				For the Nine Months Ended
	September 27, 2019				September 27, 2019
	Options		Weighted - average exercise price		Options		Weighted - average exercise price
Options outstanding at beginning of period	1,048,630		$	49.26	935,252		$	45.91
Granted	—		$	—	194,470		$	61.02
Exercised	(110,453	)	$	39.20	(173,592	)	$	37.08
Forfeited or expired	(725	)	$	62.46	(18,678	)	$	58.18
Options outstanding at September 27, 2019	937,452		$	50.44	937,452		$	50.44

Fair Value Assumptions

The fair value of each option award is estimated on the date of grant using the Black-Scholes option valuation model. The following table indicates the weighted-average assumptions used in estimating fair value:



	For the Nine Months Ended
	September 27, 2019			September 28, 2018
Expected option term (years)	4.9			4.9
Expected volatility	19.4		%	18.1		%
Risk-free interest rate	2.5		%	2.6		%
Expected dividend yield	1.3		%	1.5		%
Per share fair value of options granted		$11.18			$10.65

Restricted Stock Award and Restricted Stock Unit Activity

Restricted stock award and restricted stock unit activity were as follows:



	For the Three Months Ended				For the Nine Months Ended
	September 27, 2019				September 27, 2019
	Restricted Stock		Weighted- average grant date fair value		Restricted Stock		Weighted- average grant date fair value
Restricted Stock outstanding at beginning of period	137,880		$	54.27	143,697		$	49.97
Granted	—		$	—	63,804		$	60.86
Vested	(38,205	)	$	55.65	(102,467	)	$	52.69
Forfeited or expired	—		$	—	(5,359	)	$	57.59
Restricted Stock outstanding at September 27, 2019	99,675		$	53.74	99,675		$	53.74