Stock-Based Compensation

3 Months Ended

Mar. 31, 2013

Stock-Based Compensation [Abstract]

Stock-Based Compensation

 (11) Stock-Based Compensation

The Company's stock-based compensation expense for the three months ended March 31, 2013 included performance-based restricted stock units ("PRSUs"), non-qualified stock options, restricted stock units ("RSUs") and deferred stock units ("DSUs"). A summary of the Company's stock-based compensation expense is presented below:

(in millions)
		Three Months Ended
		March 31,
		2013		2012
PRSU expense	$	0.8	$	2.7
Option expense		2.1		1.1
RSU/DSU expense		0.6		0.6
Total stock-based compensation expense	$	3.5	$	4.4

A summary of the Company's PRSU activity and related information for the three months ended March 31, 2013 is presented below:

(shares in millions)
	Number of Shares		Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Awards outstanding at December 31, 2012		0.3	$	58.52
Granted		0.3		40.72
Vested		—		—
Forfeited		(0.3 )		58.41
Awards outstanding at March 31, 2013		0.3	$	40.72	$	8.2

The maximum number of shares to be awarded under the PRSUs granted during the three months ended March 31, 2013 will be 0.6 million and will vest, if earned, at the end of the two-year performance period ending on December 31, 2014.

During the three months ended March 31, 2013, PRSUs with an aggregate intrinsic value of $14.9 million were issued from treasury stock following the satisfaction of certain financial metrics over the performance period. The PRSUs were issued from treasury stock at 282.0% of the target award, out of a maximum payout of 300.0%.

A summary of the Company's stock option activity and related information for the three months ended March 31, 2013 is presented below:

(shares in millions)
	Number of Shares		Weighted- Average Grant Date Fair Value		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Options outstanding December 31, 2012		2.9	$	17.00
Granted		0.6		38.91
Forfeited		—		—
Exercised		0.3		14.43
Options outstanding at March 31, 2013		3.2	$	21.19		6.63	$	30.9
Options exercisable at March 31, 2013		2.2	$	14.22		5.24	$	37.4

The aggregate intrinsic value of options exercised during the three months ended March 31, 2013 and 2012 was $7.5 million and $34.4 million, respectively.

A summary of the Company's RSU and DSU activity and related information for the three months ended March 31, 2013 is presented below:

(shares in millions)
	Number of Shares		Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value
Awards outstanding at December 31, 2012		0.2	$	32.03
Granted		0.1		46.06
Vested		(0.2 )		28.90
Forfeited		—		—
Awards outstanding at March 31, 2013		0.1	$	47.14	$	4.5

The RSUs granted during the three months ended March 31, 2013 will vest over one year. No DSUs were granted during the three months ended March 31, 2013.

The aggregate intrinsic value of RSUs issued from treasury stock during the three months ended March 31, 2013 was $5.9 million.

A summary of total unrecognized stock-based compensation expense based on current performance estimates related to the PRSUs, options and RSUs/DSUs granted during the three months ended March 31, 2013 is presented below:

($ in millions)
	March 31, 2013		Weighted Average Remaining Vesting Period (Years)
Unrecognized PRSU expense	$	9.3		1.82
Unrecognized stock option expense		8.4		1.92
Unrecognized RSU/DSU expense		5.0		1.78
Total unrecognized stock-based compensation expense	$	22.7		1.85