Acquisitions (Proforma Revenue And Earnings Of The Combined Entity) (Details) (Angus [Member], USD $) In Thousands, unless otherwise specified	9 Months Ended
Feb. 29, 2012	Feb. 28, 2011
Angus [Member]
Proforma revenue	$ 1,912,071	$ 1,897,557
Proforma net earnings	$ 83,836	$ 76,483

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=6909870&loc=d3e1392-128463

Name:	us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration