CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Cash flows from operating activities:
Net income	$ 4,771	$ 5,697
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,168	14,691
Remeasurement (gain)/loss on foreign currency	(41)	110
Provision for losses on accounts receivable	107	57
Gain on sale of rental and lease equipment	(3,082)	(2,893)
Stock compensation expense	288	344
Excess tax benefit for share based compensation	(82)	(96)
Deferred income taxes	(1,235)	(1,435)
Change in operating assets and liabilities:
Accounts receivable	(89)	(1,765)
Other assets	(2,433)	(1,627)
Accounts payable	632	(183)
Accrued expenses	(508)	1,156
Deferred revenue	(64)	(72)
Net cash provided by operating activities	12,432	13,984
Cash flows from investing activities:
Proceeds from sale of rental and lease equipment	8,284	8,017
Payments for purchase of rental and lease equipment	(17,823)	(16,666)
Payments for purchase of other property	(61)	(151)
Net cash used in investing activities	(9,600)	(8,800)
Cash flows from financing activities:
Borrowings under bank lines of credit	8,581	9,000
Payments under bank lines of credit	(8,581)	(14,000)
Minimum tax withholdings on share based compensation	(10)	0
Excess tax benefit for share based compensation	82	96
Payment of dividends	(5,015)	(5,036)
Net cash used in financing activities	(4,943)	(9,940)
Effect of exchange rate changes on cash	139	(157)
Net decrease in cash	(1,972)	(4,913)
Cash at beginning of period	5,946	10,402
Cash at end of period	3,974	5,489
Supplemental Cash Flow Information [Abstract]
Interest paid, during the period	4	37
Net income taxes paid, during the period	369	2,891
Dividends accrued during the period, not yet paid	87	4,986
Rental equipment acquisitions, not yet paid	4,304	3,332
Used equipment sales in accounts receivable and other assets, not yet collected	7,811	9,453
Transfers of demonstration equipment to rental and lease equipment	$ 413	$ 1,388