Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Cash flows from operating activities:
Net income	$ 11,325	$ 14,524
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	28,779	26,542
Remeasurement loss on foreign currency	47	75
Provision for losses on accounts receivable	235	132
Gain on sale of rental and lease equipment	(5,845)	(4,948)
Gain on bargain purchase, net of taxes		(3,382)
Stock compensation expense	639	710
Excess tax benefit for share based compensation	(113)	(50)
Deferred income taxes	(1,885)	5,200
Change in operating assets and liabilities:
Accounts receivable	(793)	(3,958)
Other assets	596	205
Accounts payable	(1,091)	(1,556)
Accrued expenses	1,300	156
Deferred revenue	(229)	654
Net cash provided by operating activities	32,965	34,304
Cash flows from investing activities:
Proceeds from sale of rental and lease equipment	14,185	11,152
Cash paid for acquisition		(10,625)
Payments for purchase of rental and lease equipment	(35,959)	(53,773)
Payments for purchase of other property	(511)	(475)
Net cash used in investing activities	(22,285)	(53,721)
Cash flows from financing activities:
Borrowing under bank line of credit	2,000
Payment under bank line of credit	(2,000)
Minimum tax withholdings on share based compensation	(36)
Excess tax benefit for share based compensation	113	50
Payment of dividends	(9,729)	(9,653)
Net cash used in financing activities	(9,652)	(9,603)
Effect of exchange rate changes on cash	(301)	109
Net increase (decrease) in cash and cash equivalents	727	(28,911)
Cash and cash equivalents at beginning of period	9,290	41,441
Cash and cash equivalents at end of period	$ 10,017	$ 12,530