Debt (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	May 31, 2011
Revolving Loans
Revolving loans
Total Amount Committed by Lenders	$ 436.0
Outstanding Borrowings	93.0
Outstanding Letters of Credit	148.8
Total Amount Available	194.2
U.S. Dollar revolving loans under the Amended Credit Agreement
Revolving loans
Weighted Average Interest Rate (as a percent)	1.30%
Total Amount Committed by Lenders	250.0	250.0
Outstanding Borrowings	93.0
Outstanding Letters of Credit	0.6
Total Amount Available	156.4
Other revolving loans
Revolving loans
Total Amount Committed by Lenders	186.0
Outstanding Letters of Credit	148.2
Total Amount Available	$ 37.8