Notes Payable and Long-Term Debt - Line of Credit (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2011 Original multi-currency revolving credit facility	Dec. 31, 2011 Amended multi-currency revolving credit facility
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	$ 550.0	$ 650.0
Line of credit facility, maximum borrowing capacity	$ 600.0	$ 1,000.0