Share-Based Arrangements (Tables)

Stock option activity is as follows:



	Options		Weighted average- exercise price
Options outstanding at December 31, 2018	935,252		$	45.91
Granted	194,470		61.02
Exercised	(373,015	)	45.68
Forfeited or expired	(20,343	)	58.41
Options outstanding at December 31, 2019	736,364		$	49.67

The following table presents information regarding options outstanding as of December 31, 2019:



Weighted-average remaining contractual term - options outstanding (years)	6.2
Aggregate intrinsic value - options outstanding (in thousands)	$	12,171
Weighted-average exercise price - options outstanding	$	49.67
Options exercisable	312,121
Weighted-average remaining contractual term - options exercisable (years)	4.5
Aggregate intrinsic value - options exercisable (in thousands)	$	7,672
Weighted-average exercise price - options exercisable	$	41.62

22. SHARE-BASED ARRANGEMENTS (CONTINUED)

Stock Incentive Plan - continued

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:



	2019			2018			2017
Expected option term (years)	4.9			4.9			5.0
Expected volatility	19.4		%	18.1		%	19.9		%
Risk-free interest rate	2.5		%	2.6		%	1.9		%
Expected dividend yield	1.3		%	1.5		%	1.6		%
Per share fair value of options granted	$	11.18		$	10.65		$	8.61

Restricted Stock Award and Restricted Stock Unit activity is as follows:



	Restricted Stock Awards		Weighted- average grant date fair value
Restricted Stock outstanding at December 31, 2018	143,697		$	49.97
Granted	63,804		60.86
Vested	(108,517	)	52.81
Forfeited or expired	(6,184	)	57.62
Restricted Stock outstanding at December 31, 2019	92,800		$	53.63