Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

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

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

The following table summarizes the Company's pre-tax compensation expense and related income tax benefit for the years ended December 31, 2011, 2010 and 2009 related to the Company's performance units and restricted stock.

Year ended December 31 (In millions)	2011		2010		2009
Performance units
Total shareholder return	$	8.2	$	6.8	$	4.4
Earnings per share	5.5		2.5		1.4
Total performance units	13.7		9.3		5.8
Restricted stock	1.0		0.9		0.9
Total compensation expense	$	14.7	$	10.2	$	6.7
Income tax benefit	$	5.7	$	3.9	$	2.7

Performance Units Total Shareholder Return Valuation Assumptions [Table Text Block]

The number of performance units granted based on total shareholder return and the assumptions used to calculate the grant date fair value of the performance units based on total shareholder return are shown in the following table. 

	2011			2010			2009
Number of units granted	213,721			214,750			316,513
Fair value of units granted	$	46.09		$	39.43		$	25.55
Expected dividend yield	3.2		%	3.9		%	4.5		%
Expected price volatility	33.0		%	34.0		%	31.0		%
Risk-free interest rate	1.40		%	1.42		%	1.25		%
Expected life of units (in years)	2.87			2.87			2.88

Performance Units Earnings Per Share Valuation Assumptions [Table Text Block]

The number of performance units granted based on earnings per share and the grant date fair value are shown in the following table. 

	2011		2010		2009
Number of units granted	71,238		71,585		105,504
Fair value of units granted	$	41.61	$	32.44	$	20.02

Restricted Stock Valuation Assumptions [Table Text Block]

The number of shares of restricted stock granted and the grant date fair value are shown in the following table. 

	2011		2010		2009
Shares of restricted stock granted	17,902		26,653		6,226
Fair value of restricted stock granted	$	48.82	$	40.78	$	33.38

Schedule of Nonvested Share Activity [Table Text Block]

A summary of the activity for the Company's non-vested performance units and restricted stock at December 31, 2011 and changes in 2011 are shown in the following table. 

	Performance Units
	Total Shareholder Return					Earnings Per Share					Restricted Stock
	Number of Units			Weighted-Average Grant Date Fair Value		Number of Units			Weighted-Average Grant Date Fair Value		Number of Shares		Weighted-Average Grant Date Fair Value
Units/Shares Non-Vested at 12/31/10	507,154			$	31.40	169,054			$	25.26	47,739		$	36.46
Granted	213,721		(A)	$	46.09	71,238		(A)	$	41.61	17,902		$	48.82
Vested	(291,294	)		$	25.55	(97,099	)		$	20.02	(28,397	)	$	34.05
Forfeited	(14,751	)		$	40.53	(4,916	)		$	34.91	—		$	—
Units/Shares Non-Vested at 12/31/11	414,830			$	42.75	138,277			$	37.01	37,244		$	44.24
Units/Shares Expected to Vest	357,974					119,325					37,244

(A) Represents target number of units granted.  Actual number of units earned, if any, is dependent upon performance and may range from 0 percent to 200 percent of the target.

Fair Value of Vested Performance Units and Restricted Stock [Table Text Block]

A summary of the Company's fair value for its vested performance units and restricted stock is shown in the following table.

Year ended December 31 (In millions)	2011		2010		2009
Performance units
Total shareholder return	$	7.4	$	5.4	$	1.9
Earnings per share	3.9		1.9		0.5
Restricted stock	1.0		0.6		0.6

Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]

A summary of the Company's unrecognized compensation cost for its non-vested performance units and restricted stock and the weighted-average periods over which the compensation cost is expected to be recognized are shown in the following table.

December 31, 2011	Unrecognized Compensation Cost (in millions)		Weighted Average to be Recognized (in years)
Performance units
Total shareholder return	$	7.8	1.70
Earnings per share	3.0		1.56
Total performance units	10.8
Restricted stock	0.9		2.33
Total	$	11.7

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of the activity for the Company's stock options at December 31, 2011 and changes in 2011 are shown in the following table. 

(dollars in millions)	Number of Options		Weighted-Average Exercise Price		Aggregate Intrinsic Value		Weighted-Average Remaining Contractual Term
Options Outstanding at 12/31/10	100,344		$	22.19
Exercised	(44,544	)	$	20.94	$	2.2
Options Outstanding at 12/31/11	55,800		$	23.19	$	1.9	1.96	years
Options Fully Vested and Exercisable at 12/31/11	55,800		$	23.19	$	1.9	1.96	years

Exercised Stock Options [Table Text Block]

A summary of the activity for the Company's exercised stock options in 2011, 2010 and 2009 are shown in the following table. 

Year ended December 31 (In millions)	2011		2010		2009
Intrinsic value (A)	$	2.2	$	2.5	$	1.7
Cash received from stock options exercised	1.3		3.2		3.5
Income tax benefit realized for the tax deductions from exercised stock options (B)	—		1.0		0.7

(A) The difference between the market value on the date of exercise and the option exercise price.

(B) The Company did not realize an income tax benefit for the tax deductions from the exercised stock options in 2011 due to the Company being in a tax net operating loss position in 2011.