Investments (Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended
Apr. 30, 2014 Shred-it Partnership [Member]	May 31, 2014 Minimum [Member]	May 31, 2014 Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Equity method investment, recorded at fair value	$ 339.4
EBITDA Margin		20.00%	22.00%
Ratio of capital expenditures to revenues		4.50%	5.50%
Long-term revenue growth rate		1.50%	2.00%
WACC Rate		9.00%	9.00%

Fair Value Inputs, Capital Expenditures to Revenues Ratio

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- Definition

Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Margin

+ References

No definition available.

+ Details

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- Definition

Fair value portion of investments accounted under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 25

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6903542&loc=d3e32014-111567

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Percentage of assumed long-term growth in revenues, used as an input to measure fair value.

+ References

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