Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation Expense and Related Tax Benefit

Total stock-based compensation expense and the related tax benefit were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
In thousands	2021		2020		2021		2020
Stock options	$	344	$	452	$	1,055	$	1,445
Restricted stock units	5,104		4,399		16,546		18,575
Unrestricted stock awards	217		206		650		618
Phantom stock units	519		582		2,861		2,075
Total stock-based compensation	$	6,184	$	5,639	$	21,112	$	22,713
Related tax benefit	$	1,159	$	1,070	$	3,840	$	4,257

Employee Stock Options Activity

A summary of our stock option activity is as follows:

	Shares	Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value		Weighted Average Grant Date Fair Value
	(in thousands)			(years)	(in thousands)
Outstanding, January 1, 2020	458	$	56.38	7.0	$	12,641
Granted	80	84.38					$	26.21
Exercised	(49)	50.90			1,189
Forfeited	(5)	83.80
Outstanding, September 30, 2020	484	$	61.30	7.0	$	3,816
Outstanding, January 1, 2021	433	$	61.95	6.9	$	14,697
Granted	—						$	—
Exercised	(34)	67.21			1,215
Forfeited	(6)	83.33
Outstanding, September 30, 2021	393	$	61.18	6.1	$	6,496
Exercisable, September 30, 2021	317	$	56.51	5.6	$	6,361

Stock Options, Valuation Assumptions

The weighted average assumptions used to estimate the fair value of stock options granted and the resulting weighted average fair value are as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Expected volatility	—	%	41.5	%	—	%	32.1	%
Risk-free interest rate	—	%	0.3	%	—	%	1.3	%
Expected term (years)	N/A		5.3		N/A		5.3

Restricted Stock Units Award Activity

The following table summarizes restricted stock unit activity:

In thousands, except fair value	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
Outstanding, January 1, 2020	684
Granted	209	$	83.34
Released (1)	(338)			$	21,947
Forfeited	(23)
Outstanding, September 30, 2020	532
Outstanding, January 1, 2021	544	$	71.79
Granted	212	97.96
Released (1)	(288)	70.20		$	28,494
Forfeited	(46)	77.79
Outstanding, September 30, 2021	422	85.75
Vested but not released, September 30, 2021	10			$	733

(1)     Shares released is presented as gross shares and does not reflect shares withheld by us for employee payroll tax obligations.

Restricted Stock Units, Valuation Assumptions

The weighted average assumptions used to estimate the fair value of performance-based restricted stock units granted with a service and market condition and the resulting weighted average fair value are as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Expected volatility	—		%	52.6		%	50.5		%	38.2		%
Risk-free interest rate	—		%	0.2		%	0.2		%	1.5		%
Expected term (years)	N/A			2.3			2.9			1.8
Weighted average fair value	$	—		$	61.45		$	113.75		$	93.05