Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The following summarizes the significant assumptions used to determine the fair value of performance shares and related compensation expense as well as the resulting estimated fair value of performance shares granted:

	2022		2021
Risk-free interest rate	1.82	%	0.19	%
Expected life, in years	3		3
Expected volatility	28.2% to 38.8%		28.2% to 38.5%
Dividend yield	4.5	%	4.3	%

Schedule of Nonvested Share Activity

A summary of nonvested shares as of and changes during the year ended December 31, 2022, are as follows:

	Performance Unit Awards
	Shares	Weighted-Average Grant-Date Fair Value
Beginning nonvested grants	162,523	$	58.76
Granted	92,970	51.61
Vested	(58,889)	73.13
Forfeited	(2,197)	54.25
Remaining nonvested grants	194,407	$	51.04

Share-based Compensation Arrangement by Share-based Payment Award

Schedule of Nonvested Restricted Stock Units Activity

A summary of nonvested shares as of and changes during the year ended December 31, 2022, are as follows:

	Shares	Weighted-Average Grant-Date Fair Value
Beginning nonvested grants	87,319	$	49.63
Granted	25,360	47.04
Vested	(13,394)	52.20
Forfeited	—	—
Remaining nonvested grants	99,285	$	48.62

Schedule of Deferred Compensation Arrangement with Individual, Share-based Payments

Following is a summary of the components of DSUs issued and compensation expense attributable to the DSUs (in millions, except DSU amounts):

	December 31,
	2022		2021		2020
DSUs Issued	12,109		18,741		21,434
Compensation expense	$	0.7	$	1.1	$	1.5
Change in value of shares	0.1		1.3		(2.9)
Total compensation expense (benefit)	$	0.8	$	2.4	$	(1.4)
DSUs withdrawn	4,022		186,137		613
Value of DSUs withdrawn	$	0.2	$	12.1	$	0.1