Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Share-Based Compensation

Schedule of stock option activity

	Year Ended December 31,
	2015			2014			2013
		Weighted			Weighted			Weighted
		Average			Average			Average
		Exercise			Exercise			Exercise
	Shares	Price		Shares	Price		Shares	Price
Outstanding at  January 1	294,342	$	35.91	295,916	$	33.26	340,140	$	31.79
Granted	26,430		61.74	22,497		65.59	23,007		41.45
Exercised	(35,360)		31.51	(22,878)		31.06	(65,555)		28.75
Forfeited	—		—	(1,180)		31.97	(220)		27.22
Expired	(7)		31.72	(13)		27.22	(1,456)		22.17
Outstanding at December 31	285,405		38.85	294,342		35.91	295,916		33.26
Exercisable at December 31	227,130		34.48	239,417		33.17	233,566		32.66
Weighted-average fair value of options granted during the year		$	25.08		$	26.44		$	15.66

Schedule of information pertaining to options outstanding

					Options Outstanding				Options Exercisable
						Weighted					Weighted
						Average					Average
						Remaining		Weighted		Weighted	Remaining
Range of					Number	Contractual		Average	Number	Average	Contractual
Exercise Prices					Outstanding	Life		Exercise Price	Outstanding	Exercise Price	Life
$	26.01	-	$	30.00	33,313	3.3	years	27.49	33,313	27.49
$	30.01	-	$	35.00	121,000	3.6	years	31.78	114,855	31.78
$	35.01	-	$	40.00	57,659	2.1	years	38.20	57,655	38.20
$	40.01	-	$	45.00	24,507	6.9	years	41.42	13,824	41.40
$	45.01	-	$	69.48	48,926	8.6	years	63.51	7,483	65.52
					285,405	4.4	years	38.85	227,130	34.48	3.4	years

Schedule of weighted-average assumptions used in valuing options

	Year ended December 31,
	2015		2014					2013
Dividend yield	1.40	%	1.27	%				1.70	%
Expected life	8.5	years	6	years				6	years
Expected volatility	40.9	%	43.8	%	-	44.7	%	45.7	%
Risk-free interest rate	1.79	%	2.10	%				1.02	%

Summary of nonvested restricted stock

		Weighted-
		Average
		Grant-Date
Restricted Stock	Shares	Fair Value
Nonvested at January 1 2015	228,907	$	37.44
Granted	45,605		70.86
Vested	(54,730)		36.56
Forfeited	(1,500)		49.46
Nonvested at December 31, 2015	218,282		44.56

Vesting schedule of shares

	Shares
2016	70,568
2017	54,892
2018	36,720
2019	32,067
2020	5,832
Thereafter	18,203
	218,282

Summary of nonvested RSUs

		Weighted-
		Average
		Grant-Date
Restricted Stock Units	Shares	Fair Value
Nonvested at January 1, 2015	79,308	$	55.92
Granted	39,672		68.31
Vested	(38,218)		50.67
Forfeited	(973)		50.45
Nonvested at December 31, 2015	79,789		64.66