Employee Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2011

Employee Retirement Plans [Abstract]

Actuarial Assumptions

	Year Ended December 31,
	2011			2010			2009
Assumptions used to determine benefit obligations at the annual measurement date were:
Obligation discount rate		5.40	%		5.90	%		6.10	%
Compensation increase rate		3.00	%		3.00	%		3.00	%
Assumptions used to determine net periodic benefit costs were:
Obligation discount rate		5.90	%		6.10	%		6.50	%
Long-term rate of return on plan assets		7.75	%		7.75	%		7.75	%
Compensation increase rate		3.00	%		3.00	%		4.00	%

Components of net retirement cost

	Year Ended December 31,
	2011			2010			2009
	(in millions)
Expense Components
Service cost	$	0.8		$	0.9		$	3.0
Interest		19.6			18.7			19.7
Expected return on plan assets		(22.8	)		(20.1	)		(15.7	)
Amortization and deferral:
Actuarial loss		1.8			1.9			4.2
Prior service cost		0.1			0.1			0.1
Other		—			0.2			(0.4	)
Defined benefit expense		(0.5	)		1.7			10.9
Profit sharing		9.3			8.3			7.6
Net expense	$	8.8		$	10.0		$	18.5

Obligations and Funded Status

	Year Ended December 31,
	2011			2010
	(in millions)
Accumulated Benefit Obligations	$	364.8		$	335.7
Projected Benefit Obligations:
Beginning of year	$	335.8		$	326.1
Service cost		0.8			0.9
Interest		19.6			18.7
Benefits paid		(14.7	)		(12.9	)
Actuarial loss		23.3			3.3
Amendments		—			0.2
Settlements		—			(0.5	)
End of year	$	364.8		$	335.8
Plans’ Assets:
Beginning of year	$	291.1		$	257.6
Actual return on assets		(1.2	)		35.3
Employer contributions		15.4			11.6
Benefits paid		(14.7	)		(12.9	)
Settlements		—			(0.5	)
End of year	$	290.6		$	291.1
Consolidated Balance Sheet Components:
Funded status	$	(74.2	)	$	(44.7	)

Amounts Recognized in Other Comprehensive Income (Loss)

	Year Ended December 31,
	2011			2010			2009
	(in millions)
Actuarial gain (loss)	$	(47.3	)	$	11.9		$	18.7
Amortization of actuarial loss		1.7			1.9			4.2
Amortization of prior service cost		0.1			0.1			0.1
Other		—			(0.2	)		—
Curtailments		—			—			33.5
Settlements		—			0.2			—
Total before income taxes		(45.5	)		13.9			56.5
Income tax expense (benefit)		(16.9	)		5.2			20.9
Net amount recognized in other comprehensive income (loss)	$	(28.6	)	$	8.7		$	35.6

Estimated fair value of plan assets

	Target Allocation			December 31, 2011			December 31, 2010
Cash and cash equivalents					3	%		1	%
Equity securities		55-65	%		66			68
Debt securities		35-45	%		31			31
Total					100	%		100	%

Benefit payments expected to be paid in future

	Fair Value Measurement as of December 31, 2011
	(in millions)
	Level 1		Level 2		Level 3		Total
Temporary cash investments	$	9.7	$	—	$	—	$	9.7
Common trust funds		—		207.4		—		207.4
Registered investment companies		73.5		—		—		73.5
	$	83.2	$	207.4	$	—	$	290.6

	Fair Value Measurement as of December 31, 2010
	(in millions)
	Level 1		Level 2		Level 3		Total
Temporary cash investments	$	3.5	$	—	$	—	$	3.5
Common trust funds		—		210.3		—		210.3
Registered investment companies		71.7		—		—		71.7
Corporate stock		2.9		—		—		2.9
Corporate bonds		2.0		—		—		2.0
U.S. government obligations		0.7		—		—		0.7
	$	80.8	$	210.3	$	—	$	291.1