Pension and Savings Plans (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Change in benefit obligation:
Fair value of plan assets at end of period	$ 813.7	$ 769.6
Pension Plans, Defined Benefit [Member]
Change in benefit obligation:
Projected benefit obligation at beginning of period	963.6	881.0
Service cost	2.0	1.7	1.5
Interest cost	46.7	49.8	50.5
Benefits paid	(54.1)	(52.8)
Actuarial loss	100.4	83.9
Projected benefit obligation at end of period	1,058.6	963.6	881.0
Fair value of plan assets at beginning of period	769.6	771.6
Actual return on plan assets	96.5	4.1
Employer contributions	1.7	46.7
Benefits paid	(54.1)	(52.8)
Fair value of plan assets at end of period	813.7	769.6	771.6
Funded status at end of year	(244.9)	(194.0)
Amounts recognized in the consolidated balance sheets:
Current obligation (included in Accounts payable and accrued expenses)	(1.7)	(1.7)
Noncurrent obligation (included in Other noncurrent liabilities)	(243.2)	(192.3)
Net amount recognized	$ (244.9)	$ (194.0)