Stock Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Valuation Assumptions for All Awards Issued

The table below includes the assumptions for all awards issued:

	2017		2016			2015
SOs
Risk-free interest rate		—		—			1.1	%
Dividend yield 1)		—		—			2.3	%
Expected life in years		—		—			3.4
Expected volatility		—		—			24.0	%
PSs and RSUs
Dividend yield 2)		—		2.2	%		—

1) The dividend yield assumption is used for both SOs and the RSUs granted in 2015.

2) Dividend equivalent rights applied to LTI program starting 2017.

Schedule of Number of Restricted Stock Units and Performance Shares

Information on the number of RSUs, PSs and SOs related to the Stock Incentive Plan during the period of 2015 to 2017 is as follows.

RSUs	2017			2016			2015
Weighted average fair value at grant date	$	105.64		$	100.77		$	105.87
Outstanding at beginning of year		188,494			204,552			198,285
Granted		84,771			71,870			74,908
Shares issued		(70,795	)		(66,651	)		(58,186	)
Cancelled/Forfeited/Expired		(14,060	)		(21,277	)		(10,455	)
Outstanding at end of year		188,410			188,494			204,552

PSs	2017			2016			2015
Weighted average fair value at grant date	$	105.87		$	98.57		N/A
Outstanding at beginning of year		138,548			—		N/A
Change in performance conditions		(69,274	)		—		N/A
Granted		75,379			143,740		N/A
Shares issued		—			—		N/A
Cancelled/Forfeited/Expired		(4,762	)		(5,192	)	N/A
Outstanding at end of year		139,891			138,548		N/A

Schedule of Options Exercisable

Information on the number of RSUs, PSs and SOs related to the Stock Incentive Plan during the period of 2015 to 2017 is as follows.

SOs	Number of options			Weighted average exercise price
Outstanding at Dec 31, 2014		538,825		$	70.38
Granted		187,996			113.51
Exercised		(244,182	)		68.82
Cancelled/Forfeited/Expired		(9,588	)		92.70
Outstanding at Dec 31, 2015		473,051		$	87.88
Granted		—			—
Exercised		(51,084	)		88.10
Cancelled/Forfeited/Expired		(10,858	)		102.31
Outstanding at Dec 31, 2016		411,109		$	87.47
Granted		—			—
Exercised		(100,184	)		79.58
Cancelled/Forfeited/Expired		(10,976	)		112.20
Outstanding at Dec 31, 2017		299,949		$	89.20
OPTIONS EXERCISABLE
At December 31, 2015		290,487		$	71.76
At December 31, 2016		254,842		$	71.48
At December 31, 2017		299,949		$	89.20

Summary of Stock Options Outstanding and Exercisable

The following summarizes information about SOs outstanding and exercisable at December 31, 2017:

RANGE OF EXERCISE PRICES	Number outstanding		Remaining contract life (in years)		Weighted average exercise price
$16.31 – $19.96		13,744		1.14	$	16.31
$44.70 – $49.60		17,125		2.14	$	44.70
$51.67 – $59.01		6,875		0.14	$	51.67
$67.00 – $69.18		51,450		4.76	$	68.35
$72.95 – $94.87		87,474		5.55	$	90.52
$113.36 – $126.46		123,281		7.13	$	113.36
		299,949		5.54	$	89.20

RANGE OF EXERCISE PRICES	Number exercisable		Remaining contract life (in years)		Weighted average exercise price
$16.31 – $19.96		13,744		1.14	$	16.31
$44.70 – $49.60		17,125		2.14	$	44.70
$51.67 – $59.01		6,875		0.14	$	51.67
$67.00 – $69.18		51,450		4.76	$	68.35
$72.95 – $94.87		87,474		5.55	$	90.52
$113.36 – $126.46		123,281		7.13	$	113.36
		299,949		5.54	$	89.20