Retirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended						3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2010 Muncie Plant [Member]	Dec. 31, 2011 Muncie Plant [Member]
Defined Benefit Plan Disclosure [Line Items]
Recognized net (gain) loss due to settlements	$ 5.7
Employer contribution							23.0	15.0
Estimated future employer contributions in next fiscal year					15	25
Outstanding letters of credit	59.1	58.5
Expense for defined contribution and defined benefit pension plans and other post employment defined benefit plans
Defined contribution expense	24.8	18.9	19.2
Defined benefit pension expense	27.3	17.5	19.8
Other postretirement benefit expense	11.1	13.5	17.5
Total	63.2	49.9	56.5
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year, Under Contractual Obligation				$ 7.1