Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

Share-Based Compensation

Schedule of stock option activity

				Weighted
		Weighted		Average	Aggregate
		Average		Remaining	Intrinsic
	Shares	Price		(Yrs.)	(000's)
Outstanding at January 1, 2018	218,689	$	52.75
Granted	34,407		91.05
Exercised	(33,424)		30.88
Forfeited	(5,806)		91.35
Outstanding at June 30, 2018	213,866		61.28	6.14	$	5,643
Exercisable at June 30, 2018	140,115		49.41	4.80	$	5,198
Weighted-average fair value of options granted during the year	$ 28.01

Schedule of weighted-average assumptions used in valuing options

	Six months ended June 30,
	2018		2017
Dividend yield	1.46	%	1.40	%
Expected life	8.5	years	8.5	years
Expected volatility	28.0	%	37.2	%
Risk-free interest rate	2.54	%	2.43	%

Summary of nonvested restricted stock

Nonvested restricted stock for the six months ended June 30, 2018 is summarized in the following table.  All information has been retroactively adjusted for stock dividends and stock splits.

		Weighted-
		Average
		Grant-Date
Restricted Stock	Shares	Fair Value
Nonvested at January 1, 2018	142,692	$	59.66
Granted	7,836		87.37
Vested	(18,688)		66.61
Nonvested at June 30, 2018	131,840		60.32

Summary of nonvested RSUs

Nonvested RSUs for the six months ended June 30,  2018 is summarized in the following table.

		Weighted-
		Average
		Grant-Date
Restricted Stock Units	Shares	Fair Value
Nonvested at January 1, 2018	140,036	$	78.49
Granted	100,186		86.34
Vested	(1,176)		84.35
Forfeited	(217)		92.05
LTIP Adjustment	(3,213)		89.40
Nonvested at June 30, 2018	235,616		81.64