Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2022

Equity Incentive Plan

Schedule of restricted share activity

Restricted share activity is summarized as follows:

	Shares	Weighted Average
	Outstanding	Grant Date
	(in thousands)	Fair Value
Unvested restricted stock at December 31, 2019	194	$	50.71
Restricted stock granted	52	$	78.43
Restricted stock vested	(68)	$	45.78
Restricted stock forfeited	(3)	$	63.80
Unvested restricted stock at December 31, 2020	175	$	60.53
Restricted stock granted	87	$	65.23
Restricted stock vested	(64)	$	53.82
Restricted stock forfeited	(23)	$	63.88
Unvested restricted stock at December 31, 2021	175	$	64.90
Restricted stock granted	81	$	63.10
Restricted stock vested	(63)	$	60.84
Restricted stock forfeited	(10)	$	65.12
Unvested restricted stock at December 31, 2022	183	$	65.46

Schedule of valuation assumptions used

The following assumptions were used when determining the grant date fair value:

	2022		2021		2020
Expected term (years)	2.9		2.9		2.9
Volatility	33.5	%	33.9	%	18.4	%
Risk-free rate	1.8	%	0.2	%	1.3	%

Schedule of performance share and unit activity

Performance unit and share activity is summarized as follows:

	Target Number	Weighted Average
	of Awards	Grant Date
	(in thousands)	Fair Value
Performance units and shares at December 31, 2019 - three-year performance period to be completed	61	$	61.04
Performance units granted	26	$	90.17
Performance units and shares at December 31, 2020 - three-year performance period to be completed	87	$	69.61
Performance units granted	43	$	63.42
Performance units and shares at December 31, 2021 - three-year performance period completed	(31)	$	55.29
Performance units and shares forfeited	(21)	$	68.79
Performance units and shares at December 31, 2021 - three-year performance period to be completed	78	$	72.13
Performance units granted	34	$	68.59
Performance units and shares at December 31, 2022- three-year performance period completed	(27)	$	66.96
Performance units and shares at December 31, 2022 - three-year performance period to be completed	85	$	72.27

	Shares	Weighted Average
	Outstanding	Grant Date
	(in thousands)	Fair Value
Performance shares - three-year performance period completed but not yet vested at December 31, 2020	—	$	—
Shares earned at completion of three-year performance period (1)	47	$	55.29
Shares vested	(16)	$	55.29
Shares forfeited	(4)	$	55.29
Performance shares - three-year performance period completed but not yet vested December 31, 2021	27	$	55.29
Shares earned at completion of three-year performance period (2)	28	$	66.96
Shares vested	(23)	$	59.91
Performance shares - three-year performance period completed but not yet vested December 31, 2022	32	$	61.91
(1)Performance shares granted in 2018 for which the three-year performance period was completed in 2021 paid out at the 150% performance level
(2)Performance shares granted in 2019 for which the three-year performance period was completed in 2022 paid out at the 106% performance level