Stock Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Transactions of the Company's stock option plans

The following table summarizes the transactions of the Company’s stock option plans for the three-year period ended December 31, 2015:



	Number of shares		Weighted-average exercise price
Options outstanding - December 31, 2012	247,580		$	34.26
Options granted	23,258		$	51.29
Options exercised	(66,660	)	$	24.91
Options forfeited	(1,800	)	$	37.78
Options outstanding - December 31, 2013	202,378		$	39.27
Options granted	23,958		$	54.36
Options exercised	(23,016	)	$	32.57
Options forfeited	—		n/a
Options outstanding - December 31, 2014	203,320		$	41.80
Options granted	24,755		$	56.66
Options exercised	(43,269	)	$	37.96
Options forfeited	—		n/a
Options outstanding - December 31, 2015	184,806		$	44.69
Price range $24.94 — $36.59
(weighted-average contractual life of 5.8 years)	59,500		$	35.87
Price range $36.60 — $51.29
(weighted-average contractual life of 5.0 years)	62,434		$	42.83
Price range $51.30 — $56.66
(weighted-average contractual life of 3.5 years)	62,872		$	54.89
Options outstanding - December 31, 2015	184,806
Exercisable options —
December 31, 2013	113,060		$	38.18
December 31, 2014	111,016		$	39.68
December 31, 2015	105,470		$	40.96

Assumptions used for valuing options

The following assumptions were used for valuing options granted in the years ended December 31:



	2015		2014
Per share fair value of options granted during the period	$23.08		$22.35
Risk-free interest rate	1.74	%	1.73	%
Dividend yield	1.32	%	1.31	%
Volatility factor	49.5	%	49.9	%
Weighted-average expected life in years	5.3		5.3

Aggregate intrinsic value related to stock options

The following table summarizes the aggregate intrinsic value related to options exercised, outstanding and exercisable as of and for the years ended December 31:



	2015		2014
	(In thousands)
Exercised	$	1,058	$	493
Outstanding	$	2,569	$	3,568
Exercisable	$	1,859	$	2,184

Transactions of the Company's restricted stock

The fair value of nonvested shares is determined based on the market price of the shares on the grant date.



	Shares		Fair value per share
Nonvested at December 31, 2012	73,825		$	37.01
Granted	21,425		$	51.12
Vested	(16,875	)	$	38.41
Forfeited	(3,900	)	$	37.69
Nonvested at December 31, 2013	74,475		$	40.54
Granted	21,956		$	54.36
Vested	(24,350	)	$	36.59
Forfeited	(3,625	)	$	41.61
Nonvested at December 31, 2014	68,456		$	46.32
Granted	19,193		$	56.66
Vested	(26,075	)	$	36.15
Forfeited	(1,450	)	$	48.87
Nonvested at December 31, 2015	60,124		$	53.97