Equity-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2020

The following table details our compensation expense and the related income tax benefit for the years ended December 31:

(in thousands)	2020		2019		2018
Employee equity-based compensation expense:
Performance stock awards	$	5,083	$	4,605	$	4,157
Restricted stock units		2,904		2,595		2,024
Deferred compensation stock equivalent units expense		76		72		213
Accelerated share-based termination benefits in connection with the merger		—		—		1,812
Total equity-based compensation expense	$	8,063	$	7,272	$	8,206

Total tax benefit recognized for shared-based payment awards	$	357	$	314	$	332

The following table presents the key inputs used in calculating the fair value of the PSAs and the resulting fair values:

	Year Ended December 31,
	2020			2019			2018
Stock price as of valuation date	$	42.16		$	35.01		$	54.00
Risk-free rate		1.42	%		2.47	%		2.46	%
Expected volatility		25.74	%		25.15	%		23.74	%
Expected dividend yield¹		—			—			2.96	%
Expected term (years)		3.00			3.00			3.00
Fair value of a performance share	$	45.04		$	37.87		$	75.37

¹	^{Full dividend reinvestment assumed in 2020 and 2019.}

The following table summarizes outstanding PSAs as of December 31 and the changes during each year:

	2020					2019					2018
(in thousands, except per share amounts)	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Nonvested shares outstanding at January 1		196,007		$	50.15		142,238		$	63.91		200,631		$	39.19
Granted		125,001		$	45.04		142,066		$	37.87		67,747		$	75.37
Vested		(63,456	)	$	75.37		(75,048	)	$	53.85		(121,058	)	$	30.02
Forfeited		(4,286	)	$	47.07		(13,249	)	$	45.35		(5,082	)	$	47.90
Nonvested shares outstanding at December 31		253,266		$	41.36		196,007		$	50.15		142,238		$	63.91
Total grant date fair value of PSAs vested during the year	$	4,783				$	4,041				$	3,634
Total fair value of PSAs vested during the year	$	3,968				$	3,561				$	6,397
Aggregate intrinsic value of nonvested PSAs at December 31	$	12,668				$	8,481				$	4,500

The following table summarizes outstanding RSU awards as of December 31 and the changes during each year:

	2020					2019					2018
(in thousands, except per share amounts)	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Nonvested shares outstanding at January 1		127,471		$	39.83		72,020		$	47.66		67,871		$	32.87
Granted		68,263		$	38.77		104,488		$	36.80		49,193		$	49.96
Vested		(52,908	)	$	44.48		(43,102	)	$	45.51		(41,350	)	$	26.33
Forfeited		(3,334	)	$	40.20		(5,935	)	$	40.26		(3,694	)	$	45.36
Nonvested shares outstanding at December 31		139,492		$	37.54		127,471		$	39.83		72,020		$	47.66
Total grant date fair value of RSU awards vested during the year	$	2,354				$	1,961				$	1,089
Total fair value of RSU awards vested during the year	$	2,196				$	1,771				$	1,328
Aggregate intrinsic value of nonvested RSU awards at December 31	$	6,977				$	5,516				$	2,279