Stock-based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2020

Information on the Company’s stock options is summarized below.

YEARS ENDED DECEMBER 31	2020					2019					2018
(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding, beginning of year		1,121,559		$	87.88		1,099,076		$	85.75		1,062,177		$	75.53
Granted (1)		242,598			118.34		252,813			119.36		301,152			110.98
Exercised		(54,721	)		75.86		(191,601	)		71.20		(210,190	)		69.41
Forfeited or cancelled		(27,158	)		112.18		(38,729	)		107.34		(54,063	)		89.09
Outstanding, end of year		1,282,278		$	93.64		1,121,559		$	87.88		1,099,076		$	85.75
Exercisable, end of year		852,804		$	82.76		662,555		$	75.63		515,286		$	69.83

(1)	In accordance with plan provisions, 2019 includes 67,605 options related to special dividends paid by the Company in January 2019 and December 2019, in order to retain the intrinsic value of outstanding awards. The remaining 185,208 option awards were granted at an exercise price of $119.36.

Additional information about employee options outstanding and exercisable at December 31, 2020 is included in the following table:

		Options Outstanding						Options Currently Exercisable
Range of Exercise Prices		Number		Weighted Average Remaining Contractual Lives		Weighted Average Exercise Price		Number		Weighted Average Exercise Price
$	34.66 to $40.01		42,573		1.81	$	38.33		42,573	$	38.33
$	54.61		66,107		3.14		54.61		66,107		54.61
$	66.14 to $68.41		102,996		4.16		66.15		102,996		66.15
$	70.51 to $77.91		154,014		5.35		75.45		154,014		75.45
$	82.39 to $92.68		246,844		6.22		85.39		244,951		85.33
$	104.11 to $105.53		266,274		7.16		104.12		181,613		104.12
$	113.32 to $118.54		403,470		8.75		117.96		60,550		117.07

The following significant assumptions were used to determine the fair value for options granted in the years indicated.

	2020			2019		2018
Dividend yield	2.193% to 2.805		%	2.011	%	1.740% to 1.954	%
Expected volatility	17.671% to 24.495		%	18.495% to 19.100	%	17.943% to 18.500	%
Weighted average expected volatility		18.10	%	18.86	%	18.20	%
Risk-free interest rate	0.262 to 1.042%		%	2.527% to 2.617	%	2.365% to 2.969	%
Expected term, in years	2.5 to 6.5			2.5 to 6.5		2.5 to 6.0

The following table summarizes information about employee restricted stock units:

YEARS ENDED DECEMBER 31	2020					2019					2018
	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Time-based restricted stock units:
Outstanding, beginning of year		335,166		$	109.55		332,481		$	97.28		298,528		$	83.45
Granted		143,128			117.72		149,698			117.60		152,529			111.66
Vested		(94,993	)		94.54		(109,493	)		84.57		(72,710	)		72.69
Forfeited ⁽¹⁾		(32,821	)		115.74		(37,520	)		106.03		(45,866	)		94.04
Outstanding, end of year		350,480		$	116.37		335,166		$	109.55		332,481		$	97.28
Performance and market-based restricted stock units:
Outstanding, beginning of year		86,252		$	110.70		69,838		$	95.58		102,586		$	81.21
Granted		54,415			105.10		42,605			116.67		35,063			118.60
Vested		(40,601	)		80.92		(23,521	)		79.57		(14,032	)		70.24
Forfeited ⁽¹⁾		(3,023	)		124.78		(2,670	)		135.92		(53,779	)		89.79
Outstanding, end of year		97,043		$	119.59		86,252		$	110.70		69,838		$	95.58

(1)	As a result of the sale of Chaucer and included in forfeitures in 2018 are 19,655 shares of time-based restricted stock units, 43,449 shares of performance-based restricted stock units and 2,705 shares of market-based restricted stock units that were awarded to Chaucer employees.