Employee Retirement Plans (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended			24 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012
Employee Retirement Plans (Textual) [Abstract]
Unfunded status of plans	74.2	44.7
Plan assets expected to be returned	$ 0
Prior service cost	0.3
Net of income taxes related to prior service cost	0.2
Unrecognized actuarial losses	112.1
Net of income taxes related to unrecognized actuarial losses	70.5
Actuarial loss expected to be recognized in net periodic pension cost				3.4
Net of income taxes related to actuarial loss expected to be recognized				2.2
Actual contribution by the employer in 2011	15.4	11.6
Reduction in accrued pension liability			44.1
Defined Benefit Plans [Member]
Employee Retirement Plans (Textual) [Abstract]
Expected total contribution by the employer in 2012	17.3
Actual contribution by the employer in 2011	15.4
Supplemental Profit Sharing Plan [Member]
Employee Retirement Plans (Textual) [Abstract]
Expected total contribution by the employer in 2012	9.3
Actual contribution by the employer in 2011	$ 8.2	$ 7.9	$ 7.4