Supplemental Cash Flow Information - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Aug. 31, 2013	Aug. 31, 2012
Noncash or Part Noncash Acquisitions [Line Items]
Dividends accrued	$ 4,986	$ 123
Rental And Lease Equipment
Noncash or Part Noncash Acquisitions [Line Items]
Accounts payable related to acquired rental and lease equipment	3,332	3,448
Accounts Receivable And Net Investment In Sales-Type Leases
Noncash or Part Noncash Acquisitions [Line Items]
Sales of used equipment, not yet collected	9,453	11,313
Demonstration Equipment
Noncash or Part Noncash Acquisitions [Line Items]
Transferred demonstration equipment to rental and lease equipment during the period	$ 1,388	$ 1,623

Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph a

-Article 7

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph 5

-Article 9

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant