Employee Benefit Plans (Details) - Schedule of expected future benefit payments (USD $) In Millions, unless otherwise specified	May 31, 2013
Benefit Payments [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]
Employee Benefit Plans (Details) - Schedule of expected future benefit payments [Line Items]
2014	$ 2.9
2015	2.9
2016	2.9
2017	2.9
2018	2.8
2019-2023	13.2
Medicare Subsidy Receipts [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]
Employee Benefit Plans (Details) - Schedule of expected future benefit payments [Line Items]
2014	0.3
2015	0.3
2016	0.3
2017	0.3
2018	0.3
2019-2023	1.6
Pension Plan, Defined Benefit [Member]
Employee Benefit Plans (Details) - Schedule of expected future benefit payments [Line Items]
2014	19.1
2015	11.5
2016	11.6
2017	10.9
2018	10.7
2019-2023	$ 51.1