Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Share Based Compensation [Abstract]

Summary of Restricted Stock Activity

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

	2018					2017					2016
	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		739,732		$	77.23		786,079		$	63.44		1,007,794		$	49.47
Granted		173,144			114.63		173,199			107.57		242,835			67.48
Vested (a)		(165,547	)		72.84		(213,992	)		51.37		(443,627	)		34.11
Forfeitures		(3,738	)		78.66		(5,554	)		69.03		(20,923	)		59.63
Restricted stock at December 31		743,591		$	86.90		739,732		$	77.23		786,079		$	63.44

(a) The total fair value of awards upon vesting for the years ended December 31, 2018, 2017, and 2016 was $18.9 million,$23.3 million, and $28.8 million, respectively.

Summary of Performance Units Activity

The ROIC performance unit awards are valued at the closing price of the Company’s stock on the grant date and expensed over the requisite service period based on the most probable number of awards expected to vest. The TSR performance unit awards are valued using a Monte Carlo simulation, as the TSR component contains a market condition. A summary of the Company’s performance unit activity follows:

	2018					2017					2016
	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		226,558		$	77.07		232,088		$	62.68		175,675		$	59.94
Granted		83,515			115.35		53,070			108.19		77,017			67.57
Vested (a)		(43,369	)		71.19		(58,600	)		56.08		(20,604	)		57.58
Performance units at December 31		266,704		$	90.01		226,558		$	77.07		232,088		$	62.68

(a) The total fair value of awards upon vesting for the years ended December 31, 2018, 2017, and 2016 was $5.4 million, $7.5 million, and $1.1 million, respectively. Upon vesting of the awards in 2018, 2017, and 2016, PCA issued 46,876 shares, 67,391 shares, and 21,111 shares, respectively. For 2018, 2017, and 2016, these amounts included 3,507 shares, 8,791 shares, and 507 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,
	2018			2017			2016
Restricted stock	$	18.6		$	15.0		$	15.8
Performance units		4.9			5.6			3.9
Impact on income before income taxes		23.5			20.6			19.7
Income tax benefit		(5.9	)		(7.9	)		(7.7	)
Impact on net income	$	17.6		$	12.7		$	12.0

Unrecognized Compensation Expense for Share-Based Awards

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

	December 31, 2018
	Unrecognized Compensation Expense		Remaining Weighted Average Recognition Period (in years)
Restricted stock	$	31.7	2.4
Performance units		14.1	2.6
Total unrecognized share-based compensation expense	$	45.8	2.5