Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The following table summarizes the components of the Company’s stock-based compensation expense included in general and administrative expenses in the consolidated financial statements:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2012			2011			2012			2011
	(In millions)
Pre-tax compensation expense	$	2.5		$	3.3		$	7.0		$	6.4
Tax provision	(1.0		)	(1.3		)	(2.7		)	(2.5		)
Total stock-based compensation expense, net of tax	$	1.5		$	2.0		$	4.3		$	3.9

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The following summarizes the assumptions used in the Black-Scholes model:

Risk-free interest rate	0.86		%
Weighted average historical volatility	83.6		%
Dividend yield	—
Expected years until exercise	4.66
Forfeitures	11.0		%
Weighted average fair value of options granted	$	33.11

Schedule of Share-based Compensation, Stock Options, Activity

Option balances as of June 30, 2012 and activity related to the Company’s stock options during the six months then ended were as follows:

	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value
Outstanding at December 31, 2011	1,318,640		$	32.06
Granted	147,674		$	51.63
Exercised	(212,308	)	$	15.94
Forfeited	(24,775	)	$	39.09
Outstanding at June 30, 2012	1,229,231		$	37.05	6.87	$	13,145,000
Vested at June 30, 2012 and Expected to Vest	1,173,783		$	36.48	6.76	$	12,991,000
Exercisable at June 30, 2012	780,398		$	31.89	5.8	$	11,172,000

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

A summary of restricted stock activity for the six months ended June 30, 2012 is presented below:

	Restricted Stock		Weighted Average Grant Date Fair Value	Restricted Stock Units		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2011	486,533		$31.25	18,000		$29.32
Granted	120,123		$51.85	19,152		$52.23
Released	(154,903	)	$11.03	(3,910	)	$40.58
Forfeited	(36,976	)	$40.90	—		—
Outstanding at June 30, 2012	414,777		$43.72	33,242		$41.19