Stock-Based Compensation

3 Months Ended

Mar. 31, 2012

Stock-Based Compensation [Abstract]

Stock-Based Compensation

10. Stock-based Compensation

Compensation cost and the related tax benefits were as follows:

	Three Months Ended March  31,
(in millions)	2012			2011
Stock-based compensation expense	$	4.1		$	3.4
Tax benefit		(1.4	)		(1.2	)
Stock-based compensation expense, net of taxes	$	2.7		$	2.2

Stock Options

Information on the Company's stock option plan activity is summarized as follows:

	Three Months Ended March 31,
	2012					2011
(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding, beginning of period		2,715,430		$	38.57		2,843,909		$	39.22
Granted		517,500			36.81		297,000			46.47
Exercised		(33,224	)		32.24		(117,714	)		33.17
Forfeited or cancelled		—			—		—			—
Expired		(158,850	)		44.04		(256,250	)		57.00
Outstanding, end of period		3,040,856			38.06		2,766,945			38.61

Restricted Stock Units

The following tables summarize activity information about employee restricted stock units:

	Three Months Ended March 31,
	2012					2011
(in whole shares and dollars)	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Time-based restricted stock units:
Outstanding, beginning of period		768,529		$	40.17		838,129		$	40.93
Granted		168,750			36.93		95,503			46.49
Vested		(117,522	)		35.27		(185,253	)		45.13
Forfeited		(10,309	)		39.67		(4,380	)		45.67
Outstanding, end of period		809,448			40.21		743,999			40.57
Performance and market-based restricted stock units:
Outstanding, beginning of period		69,500		$	45.37		101,680		$	39.62
Granted		99,500			36.61		42,500			46.47
Vested		—			—		(25,055	)		45.21
Forfeited		—			—		—			—
Outstanding, end of period		169,000			40.21		119,125			40.89

Performance based restricted stock units are based upon the achievement of the performance metrics at 100%. These units have the potential to range from 0% to 150% of the shares disclosed, which varies based on grant year and individual participation level. Increases above the 100% target level are reflected as granted in the period in which the performance-based stock unit goals are achieved. Decreases below the 100% target level are reflected as forfeited.

In the first three months of 2012 the Company granted market-based awards to certain members of senior management and are reflected in the Performance and market-based restricted stock activity. The attainment of these stock units are based on the relative total shareholder return ("TSR") of the Company. This metric is based on a three-year average relative TSR as compared to a Property and Casualty Index of peer companies. The fair value of market based awards was estimated at the date of grant using a valuation model. These units have the potential to range from 0% to 133% of the shares disclosed.