Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value (USD $) In Millions, unless otherwise specified	May 31, 2013		May 31, 2012
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	$ 173.8		$ 145.8
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	3.5		7.4
Cash and Cash Equivalents [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	3.5		7.4
Equity Securities, United States [Member] | Fair Value, Inputs, Level 1 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	94.0	[1]	73.0	[1]
Equity Securities, United States [Member] | Fair Value, Inputs, Level 2 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets		[1]		[1]
Equity Securities, United States [Member] | Fair Value, Inputs, Level 3 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets		[1]		[1]
Equity Securities, United States [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	94.0	[1]	73.0	[1]
Equity Securities, International [Member] | Fair Value, Inputs, Level 1 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	16.3	[2]	11.2	[2]
Equity Securities, International [Member] | Fair Value, Inputs, Level 2 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	10.4	[2]	8.3	[2]
Equity Securities, International [Member] | Fair Value, Inputs, Level 3 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets		[2]		[2]
Equity Securities, International [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	26.7	[2]	19.5	[2]
Equity Securities, Fixed Income [Member] | Fair Value, Inputs, Level 1 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	34.4	[3]	32.2	[3]
Equity Securities, Fixed Income [Member] | Fair Value, Inputs, Level 2 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	7.4	[3]	6.4	[3]
Equity Securities, Fixed Income [Member] | Fair Value, Inputs, Level 3 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets		[3]		[3]
Equity Securities, Fixed Income [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	41.8	[3]	38.6	[3]
Annuities [Member] | Fair Value, Inputs, Level 3 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	6.1		5.8
Annuities [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	6.1		5.8
Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets		[4]		[4]
Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	1.7	[4]	1.5	[4]
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets		[4]		[4]
Real Estate [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	1.7	[4]	1.5	[4]
Fair Value, Inputs, Level 1 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	148.2		123.8
Fair Value, Inputs, Level 2 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	19.5		16.2
Fair Value, Inputs, Level 3 [Member]
Employee Benefit Plans (Details) - Schedule for measurement of benefit plan assets at fair value [Line Items]
Defined benefit plan fair value of plan assets	$ 6.1		$ 5.8

[1] Funds which invest in a diversified portfolio of publicly traded U.S. common stocks of large-cap, medium-cap and small-cap companies. There are no restrictions on these investments.

[2] Funds which invest in a diversified portfolio of publicly traded common stock of non-U.S. companies, primarily in Europe and Asia. There are no restrictions on these investments.

[3] Funds which invest in a diversified portfolio of publicly traded government bonds, corporate bonds and mortgage-backed securities. There are no restrictions on these investments.

[4] Represents assets of a non-U.S. entity plan invested in a fund whose underlying investments are comprised of properties. The fund has publicly available quoted market prices and there are no restrictions on these investments.