Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Revenues:
Rentals and leases	$ 31,704	$ 28,679	$ 95,925	$ 87,139
Sales of equipment and other revenues	28,375	30,771	84,447	76,413
Total revenues	60,079	59,450	180,372	163,552
Operating expenses:
Depreciation of rental and lease equipment	13,677	12,186	39,578	35,761
Costs of revenues other than depreciation of rental and lease equipment	22,839	24,707	67,350	60,016
Selling, general and administrative expenses	15,713	14,259	47,535	41,541
Total operating expenses	52,229	51,152	154,463	137,318
Operating profit	7,850	8,298	25,909	26,234
Gain on bargain purchase, net of deferred taxes	53		3,435	202
Interest income, net	120	38	327	257
Income before income taxes	8,023	8,336	29,671	26,693
Income tax provision	3,028	3,259	10,152	9,276
Net income	$ 4,995	$ 5,077	$ 19,519	$ 17,417
Earnings per share:
Basic	$ 0.21	$ 0.21	$ 0.81	$ 0.73
Diluted	$ 0.21	$ 0.21	$ 0.81	$ 0.72
Shares used in per share calculation:
Basic	23,983	23,978	23,981	23,972
Diluted	24,179	24,098	24,180	24,058