Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Stock-Based Compensation

Summary of granted restricted stock units and stock grants and the weighted average fair value

	2012		2011		2010
Units granted	202,278		292,242		202,341
Grant date fair value (a)	$	49.31	$	41.98	$	37.47

(a) Weighted-average grant date fair value

Summary of the status of restricted stock units and stock grants and changes during the year

The following table is a summary of the status of restricted stock units and stock grants, as of December 31, 2012 and changes during the year. 

Nonvested shares	Shares	Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2012	416,231	$	39.61
Granted	202,278	49.31
Vested	126,959	39.76
Forfeited	10,797	42.63
Nonvested at December 31, 2012	480,753	43.58

Schedule of amount of cash required to settle the payments on restricted stock units

The amount of cash required to settle the payments on restricted stock units is (dollars in millions):

Year	2012		2011		2010
2007 Grant	$	—	$	1.0	$	0.9
2008 Grant	1.9		1.6		1.5
2009 Grant	1.7		1.5		1.4
2010 Grant	0.6		0.6		—
2011 Grant	0.7		—		—

Summary of the performance shares granted and the weighted average fair value

	2012		2011		2010
Units granted (a)	185,878		175,072		178,722
Grant date fair value (b)	$	47.40	$	41.71	$	37.57

(a) Reflects the target payout level.

(b) Weighted-average grant date fair value.

Summary of the status of performance shares and changes during the year

The following table is a summary of the status of performance shares, as of December 31, 2012 and changes during the year:

Nonvested shares (a)	Shares	Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2012	347,946	$	39.64
Granted	185,878	47.40
Increase in performance factor	87,037	37.57
Vested	257,127	37.57
Forfeited	16,044	42.53
Nonvested at December 31, 2012	347,690	44.67

(a)           Nonvested shares are reflected at the target payout level.  The increase or decrease in the number of shares from the target level to the estimated actual payout level is included in the increase for performance factor amounts in the year the award vests.

Summary of stock option activity under prior equity incentive plans

The following table summarizes the option activity under prior equity incentive plans for the year ended December 31, 2012:

Options	Shares	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (dollars in thousands)
Outstanding at January 1, 2012	22,958	$	34.75
Exercised	15,033	36.05
Forfeited or expired	—	—
Outstanding at December 31, 2012	7,925	32.29		.21	$	148
Exercisable at December 31, 2012	7,925	32.29		.21	$	148