Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement, Noncash Expense [Abstract]

Stock-Based Compensation Expense and Related Tax Benefit

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

	Year Ended December 31,
In thousands	2021		2020		2019
Stock options	$	1,371	$	1,944	$	1,770
Restricted stock units	21,391		22,285		24,560
Unrestricted stock awards	856		824		630
Phantom stock units	3,242		3,720		3,301
Total stock-based compensation	$	26,860	$	28,773	$	30,261
Related tax benefit	$	4,991	$	5,086	$	5,390

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, 2019	895	$	47.93	6.2	$	4,806
Granted	76	76.55					$	26.20
Exercised (1)	(489)	43.55			15,759
Forfeited	(13)	67.34
Expired	(11)	66.24
Outstanding, December 31, 2019	458	$	56.38	7.0	$	12,641
Granted	83	84.39					$	26.37
Exercised (1)	(103)	53.99			2,061
Forfeited	(5)	83.94
Outstanding, December 31, 2020	433	$	61.95	6.9	$	14,697
Granted	—	—					$	—
Exercised (1)	(34)	67.21			1,215
Forfeited	(6)	83.33
Outstanding, December 31, 2021	393	$	61.18	5.9	$	4,737
Exercisable, December 31, 2021	320	$	56.56	5.4	$	4,681

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:

	Year Ended December 31,
	2021		2020		2019
Expected volatility	—	%	32.3	%	31.7	%
Risk-free interest rate	—	%	1.3	%	1.7	%
Expected term (years)	N/A		5.3		6.1

Restricted Stock Units Award Activity

The following table summarizes restricted stock unit activity:

	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
	In thousands			In thousands
Outstanding, January 1, 2019	817	$	59.70
Granted	404	62.97
Released (1)	(471)			$	29,304
Forfeited	(66)
Outstanding, December 31, 2019	684	$	64.38
Granted	262	83.42
Released (1)	(363)			$	23,702
Forfeited	(39)
Outstanding, December 31, 2020	544	$	71.79
Granted	230	97.66
Released (1)	(293)	70.34		$	20,639
Forfeited	(51)	78.45
Outstanding, December 31, 2021	430	$	85.77
Vested but not released, December 31, 2021	10	$	68.52	$	667

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:

	Year Ended December 31,
	2021			2020			2019
Expected volatility	54.2		%	44.9		%	31.4		%
Risk-free interest rate	0.4		%	1.0		%	2.5		%
Expected term (years)	1.9			1.8			1.6
Weighted average fair value	$	77.65		$	93.97		$	61.25

Schedule of Other Share-based Compensation, Activity

The following table summarizes phantom stock unit activity:

	Number of Phantom Stock Units	Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
	In thousands			In thousands
Outstanding, January 1, 2019	83	$	61.80
Granted	55	60.49
Released	(42)			$	2,625
Forfeited	(7)
Outstanding, December 31, 2019	89	$	62.85
Granted	38	87.27
Released	(40)			$	2,971
Forfeited	(5)
Outstanding, December 31, 2020	82	$	73.13
Granted	35	96.49
Released	(41)	70.00		$	4,100
Forfeited	(7)	86.63
Outstanding, December 31, 2021	69	$	85.47