Share-based Compensation
 9 Months Ended
Sep. 30, 2016
Share-based Compensation [Abstract]  
Share-based Compensation
Share-Based Compensation

The Company has a long-term equity incentive plan, which allows for grants of restricted stock, performance awards, stock appreciation rights, and stock options to directors, officers, and employees, as well as others who engage in services for PCA. The Company has not granted option awards since 2007. The plan, as amended, terminates May 1, 2023 and authorizes 10.6 million shares of common stock for grant over the life of the plan. As of September 30, 2016, 1.2 million shares were available for future issuance under the plan. Forfeitures are added back to the pool of shares of common stock available to be granted at a future date.

The following table presents restricted stock and performance unit award activity for the nine months ended September 30, 2016:
 
Restricted Stock
 
Performance Units
 
Shares
 
Weighted Average Grant- Date Fair Value
 
Shares
 
Weighted Average Grant- Date Fair Value
Outstanding at January 1, 2016
1,007,794

 
$
49.47

 
175,675

 
$
59.94

Granted
242,835

 
67.48

 
77,017

 
67.57

Vested (a)
(417,544
)
 
33.19

 
(20,604
)
 
57.58

Forfeitures
(18,233
)
 
58.72

 
—

 
—

Outstanding at September 30, 2016
814,852

 
$
62.98

 
232,088

 
$
62.68


___________
(a)
Upon vesting of the performance unit awards, PCA issued 21,111 shares of its common stock, which included 507 shares for dividends accrued during the vesting period.
    
Compensation Expense

Our share-based compensation expense is recorded in "Selling, general, and administrative expenses". Compensation expense for share-based awards recognized in the Consolidated Statements of Income, net of forfeitures, was as follows (dollars in millions):
 
Three Months Ended September 30
 
Nine Months Ended September 30
 
2016
 
2015
 
2016
 
2015
Restricted stock
$
3.5

 
$
3.7

 
$
12.2

 
$
11.7

Performance units
1.3

 
0.9

 
2.8

 
2.0

Total share-based compensation expense
4.8

 
4.6

 
15.0

 
13.7

Income tax benefit
(1.8
)
 
(1.8
)
 
(5.8
)
 
(5.3
)
Share-based compensation expense, net of tax benefit
$
3.0

 
$
2.8

 
$
9.2

 
$
8.4



The fair value of restricted stock and performance units is determined based on the closing price of the Company’s common stock on the grant date. As PCA’s Board of Directors has the ability to accelerate vesting of share-based awards upon an employee’s retirement, the Company accelerates the recognition of compensation expense for certain employees approaching normal retirement age.

The unrecognized compensation expense for all share-based awards at September 30, 2016 was as follows (dollars in millions):
 
September 30, 2016
 
Unrecognized Compensation Expense
 
Remaining Weighted Average Recognition Period (in years)
Restricted stock
$
30.7

 
2.9
Performance units
9.1

 
3.0
Total unrecognized share-based compensation expense
$
39.8

 
2.9