Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement, Noncash Expense [Abstract]

Summary of Restricted Stock Activity

A summary of the Company’s restricted stock activity follows:

	2021					2020					2019
	Shares			Weighted Average Grant- Date Fair Value		Shares			Weighted Average Grant- Date Fair Value		Shares			Weighted Average Grant- Date Fair Value
Restricted stock at January 1		669,102		$	102.55		716,952		$	94.50		743,591		$	86.90
Granted		173,970			134.10		204,960			94.25		199,499			95.48
Vested (a)		(182,779	)		108.59		(244,823	)		72.11		(212,809	)		68.59
Forfeitures		(8,845	)		111.73		(7,987	)		99.94		(13,329	)		98.86
Restricted stock at December 31		651,448		$	109.16		669,102		$	102.55		716,952		$	94.50

(a)The total fair value of awards upon vesting for the years ended December 31, 2021, 2020, and 2019 was $24.8 million, $23.6 million, and $19.9 million, respectively.

Summary of Performance Units Activity

A summary of the Company’s performance unit activity follows:

	2021					2020					2019
	Units			Weighted Average Grant- Date Fair Value		Units			Weighted Average Grant- Date Fair Value		Units			Weighted Average Grant- Date Fair Value
Performance units at January 1		357,417		$	103.63		323,147		$	96.56		266,704		$	90.01
Granted		95,236			140.47		111,287			99.20		109,545			97.24
Vested (b)		(74,894	)		134.53		(77,017	)		67.57		(53,102	)		65.03
Forfeitures		(19,667	)		132.58		—			—		—			—
Performance units at December 31		358,092		$	105.38		357,417		$	103.63		323,147		$	96.56

(b)The total fair value of awards upon vesting, including dividends, for the years ended December 31, 2021, 2020, and 2019 was $11.0 million, $8.5 million, and $5.5 million, respectively. Upon vesting of the awards in 2021, 2020, and 2019, PCA issued 81,577 shares, 86,015 shares, and 59,165 shares, respectively. For 2021, 2020, and 2019, these amounts included 6,683 shares, 8,998 shares, and 6,063 shares, respectively, for dividends accrued during the vesting period.

Compensation Expense for Share-Based Awards

Compensation expense for share-based awards recognized in the Consolidated Statements of Income, net of forfeitures was as follows (dollars in millions):

	Year Ended December 31,
	2021			2020			2019
Restricted stock	$	23.0		$	20.1		$	22.6
Performance units		12.5			9.9			7.8
Impact on income before income taxes		35.5			30.0			30.4
Income tax benefit		(8.9	)		(7.6	)		(7.6	)
Impact on net income	$	26.6		$	22.4		$	22.8

Unrecognized Compensation Expense for Share-Based Awards

The unrecognized compensation expense for all share-based awards was as follows (dollars in millions):

	December 31, 2021
	Unrecognized Compensation Expense		Remaining Weighted Average Recognition Period (in years)
Restricted stock	$	26.1	2.4
Performance units		17.9	2.1
Total unrecognized share-based compensation expense	$	44.0		2.3