Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2013

Employee Benefit and Other Plans [Abstract]

Schedule of Employee Benefit Plans

We recorded share-based compensation expense as follows:

	For the three months ended September 30,				For the nine months ended September 30,
	2013		2012		2013		2012
	(in millions)
Share-based compensation expense	$	3.1	$	1.6	$	8.2	$	7.0

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award

Stock options: The following table summarizes information related to our common stock options:

	Number of Stock Options		Weighted Average Exercise Price
Options outstanding at January 1, 2013	5,519,345		$	11.78
Granted	1,167,559		$	21.39
Exercised	(736,806	)	$	11.48
Canceled or forfeited	(238,450	)	$	12.99
Options outstanding at September 30, 2013	5,711,648		$	13.73
Options exercisable at September 30, 2013	2,679,639		$	12.59
Expected to vest after September 30, 2013	2,298,795		$	14.98

Schedule of Stock Option Activity

The following information is provided for our stock options:

	For the nine months ended September 30,
	2013		2012
Weighted-average grant date fair value	$	10.53	$	4.97

Schedule of Restricted Stock Units Activity

Restricted Stock Units: The following table summarizes information related to our restricted stock units:

	Number of Shares		Weighted Average Grant Date Fair Value
Unvested shares at January 1, 2013	220,537		$	11.33
Granted	629,438		$	19.92
Vested	(135,811	)	$	15.13
Canceled or forfeited	(35,115	)	$	15.05
Unvested shares at September 30, 2013	679,049		$	18.34

Schedule of Performance Stock Units Activity

Performance Stock Units: The following table summarizes information related to our performance stock units:

	Number of Shares		Weighted Average Grant Date Fair Value
Unvested shares at January 1, 2013	—		$	—
Granted	442,540		$	22.84
Canceled or forfeited	(10,682	)	$	25.14
Unvested shares at September 30, 2013	431,858		$	22.79