Share-based compensation plans (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Activity related to restricted stock units

The activity related to restricted stock units for the year ended December 31, 2020 is as follows:

	Nonvested	Vested	Total	Average Grant Date Fair Value Per Share
Outstanding, December 31, 2019	156,577	94,708	251,285	$	46.14
Granted	146,937	—	146,937	$	54.16
Vested	(63,976)	63,976	—
Converted	—	(85,612)	(85,612)	$	45.29
Cancelled	(32,305)	—	(32,305)	$	50.32
Dividend equivalents	2,350	2,791	5,141	$	54.28
Outstanding, December 31, 2020	209,583	75,863	285,446	$	50.19

Activity related to performance contingent restricted stock units

The activity related to performance contingent restricted stock units for the year ended December 31, 2020 is as follows:

	Nonvested	Vested	Total	Average Grant Date Fair Value per Share
Outstanding, December 31, 2019	298,836	233,097	531,933	$44.65
Granted	153,219	—	153,219	$52.00
Performance adjustments	(125,917)	—	(125,917)	$51.03
Vested	(139,886)	139,886	—
Converted	—	(208,850)	(208,850)	$37.95
Cancelled	(29,130)	—	(29,130)	$55.04
Dividend equivalents	—	2,299	2,299	$59.43
Outstanding, December 31, 2020	157,122	166,432	323,554	$49.15

Estimated fair values of all SARs applying assumptions

The Company computed the estimated fair values of all SARs granted during 2019 and 2018 using the Black-Scholes option-pricing model applying the assumptions set forth in the following table:

	2019		2018
Expected dividend yield	2.7	%	3.1	%
Expected stock price volatility	16.6	%	16.2	%
Risk-free interest rate	2.6	%	2.8	%
Expected life of SARs	6 years		6 years

Company's SARs

The activity related to the Company’s SARs for the year ended December 31, 2020 is as follows: 

	Nonvested	Vested	Total	Weighted- average Exercise Price
Outstanding, December 31, 2019	907,013	655,110	1,562,123	$	52.95
Vested	(482,857)	482,857	—
Granted	—	—	—	$	—
Exercised	—	(224,257)	(224,257)	$	46.89
Forfeited/Expired	(26,479)	(39,959)	(66,438)	$	57.48
Outstanding, December 31, 2020	397,677	873,751	1,271,428	$	53.83
Exercisable, December 31, 2020	—	873,751	873,751	$	47.69

Schedule of other share-based compensation, activity

The activity related to deferred compensation for equity award units granted to both employees and non-employee directors combined is as follows:

	Total
Outstanding, December 31, 2019	367,147
Deferred	53,272
Converted	(59,971)
Dividend equivalents	11,965
Outstanding, December 31, 2020	372,413