Employee Benefit Plans - Textual (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 Y	Dec. 31, 2012	Dec. 31, 2011
Employee Benefit Plans [Abstract]
Company Healthcare Plans, Total Costs Net of Employee Contributions	$ 73.4	$ 67.8	$ 66.8
Retirement Investment Plan, Maximum Employee Contribution	100.00%
Retirement Investment Plan, Company Match	50% of the first 6% of each participant’s elective deferrals
Retirement Investment Plan, Age Requirement	21
Retirement Investment Plan, Company Match, Vesting Percentage	100.00%
Retirement Investment Plan, Company Match, Vesting Period	3
Retirement Investment Plan, Company Match, Total Costs	13.2	13.2	12.6
Retirement Investment Plan, Company Match, Funded by Plan Forfeiture Account	0.5	0.8	1.7
Senior Management Bonus Program, Total Costs	$ 12.4	$ 11.4	$ 12.8