Stock-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2011

Stock-Based Compensation Plans [Abstract]

Schedule of stock -based compensation expense in operations

	For the Years Ended December 31,
	2011		2010		2009
Compensation expense (1)	$	13.7	$	15.4	$	12.8

Schedule of excess tax benefit in cash flows

	For the Years Ended December 31,
	2011		2010		2009
Excess tax benefits	$	1.4	$	5.3	$	4.9

Schedule of information on performance share units

	For the Years Ended December 31,
	2011			2010			2009
Performance Share Units:
Compensation expense	$	1.7		$	4.1		$	1.8
Weighted-average grant date fair value		31.78			44.85			35.26
Payout levels for shares paid		0.0	%		127.7	%		200.0	%

Summary of status of undistributed performance share units

	Year Ended December 31, 2011
	Shares			Weighted-Average Grant  Date Fair Value per Share
Undistributed performance share units:
Undistributed as of December 31, 2010		0.8		$	33.90
Granted		0.3			31.78
Additional shares earned		(0.2	)		32.92
Distributed		—			—
Forfeited		—			35.45
Undistributed as of December 31, 2011(1)		0.9			33.40

Fair value of share units and tax deductions

	For the Years Ended December 31,
	2011		2010		2009
Fair value of performance share units distributed	$	—	$	13.2	$	9.6
Realized tax benefits from tax deductions		—		5.0		3.7

Schedule of information on restricted stock units

	For the Years Ended December 31,
	2011		2010		2009
Restricted Stock Units:
Compensation expense	$	6.6	$	6.6	$	6.6
Weighted-average grant date fair value		32.34		44.80		35.09

Summary of non vested restricted stock units

	Year Ended December 31, 2011
	Shares			Weighted-Average Grant  Date Fair Value per Share
Nonvested restricted stock units:
Nonvested as of December 31, 2010		0.6		$	34.44
Granted		0.3			32.34
Vested		(0.3	)		26.91
Forfeited		—			35.80
Nonvested as of December 31, 2011		0.6			36.51

	For the Years Ended December 31,
	2011		2010		2009
Fair value of restricted stock units vested	$	8.8	$	9.4	$	8.3
Realized tax benefits from tax deductions		3.4		3.6		3.2

Summary of stock appreciation rights

	For the Years Ended December 31,
	2011		2010		2009
Stock Appreciation Rights:
Compensation expense	$	5.4	$	4.7	$	4.4
Weighted-average grant date fair value		9.39		13.75		10.96

Summary of stock appreciation rights activity

	For the Years Ended December 31,
	2011			2010			2009
Expected dividend yield		2.39	%		1.46	%		1.57	%
Risk-free interest rate		0.62	%		1.46	%		1.78	%
Expected volatility		41.94	%		39.93	%		39.81	%
Expected life (in years)		4.07			4.04			4.12

	For the Years Ended December 31,
	2011					2010					2009
	Shares			Weighted- Average Exercise Price per Share		Shares			Weighted- Average Exercise Price per Share		Shares			Weighted- Average Exercise Price per Share
Outstanding at beginning of year		2.5		$	34.89		2.9		$	31.06		2.7		$	29.59
Granted		0.7			34.06		0.5			46.78		0.6			36.94
Exercised		(0.2	)		31.67		(0.7	)		27.20		(0.2	)		28.31
Forfeited		(0.1	)		39.39		(0.2	)		31.97		(0.2	)		30.59
Outstanding at end of year		2.9		$	34.85		2.5		$	34.89		2.9		$	31.06
Exercisable at end of year		1.8		$	33.05		1.5		$	31.81		1.6		$	29.58

Summary of stock appreciation rights outstanding

	Stock Appreciation Rights Outstanding				Stock Appreciation Rights Exercisable
Range of Exercise Prices per Share	Weighted-Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value		Weighted-Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value
$28.24 – $46.78		4.7		4.5		3.6		4.5

The Schedule of total intrinsic value of stock appreciation rights exercised

	For the Years Ended December 31,
	2011		2010		2009
Intrinsic value of stock appreciation rights exercised	$	4.2	$	10.1	$	1.5
Realized tax benefits from tax deductions		1.6		3.9		0.6