Goodwill and Intangible Assets, Net of Accumulated Amortization (Details) - USD ($) $ in Millions	Aug. 31, 2015	May. 31, 2015
Components of intangible assets, at cost
Client lists	$ 247.9	$ 244.6
Other intangible assets	3.2	3.2
Total intangible assets, gross	251.1	247.8
Less: Accumulated amortization	218.1	215.4
Intangible assets, net of accumulated amortization	33.0	$ 32.4
Estimated future amortization expense relating to intangible assets
Fiscal year ending May 31, 2016	12.0
Fiscal year ending May 31, 2017	8.9
Fiscal year ending May 31, 2018	6.1
Fiscal year ending May 31, 2019	4.1
Fiscal year ending May 31, 2020	$ 2.4

Gross carrying amount before accumulated amortization as of the balance sheet date of an asset comprised of customer information, acquired in a business combination or other transaction, having a finite beneficial life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant

- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References