Debt and Credit Facilities (Short-Term Borrowings and Current Maturities of Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Short-term borrowings and current maturities of long-term debt	$ 765.6	$ 763.3
Debentures With Put Feature [Member]
Short-term borrowings and current maturities of long-term debt	343.6	343.6
Exchangeable Senior Notes [Member]
Short-term borrowings and current maturities of long-term debt	344.0	341.2
Current Maturities Of Long Term Debt [Member]
Short-term borrowings and current maturities of long-term debt	11.4	12.5
Other Short Term Borrowings [Member]
Short-term borrowings and current maturities of long-term debt	$ 66.6	$ 66.0