Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 8,685	$ 8,213
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax expense (benefit)	339	(278)
Depreciation	1,771	1,399
Amortization	60	98
Stock-based compensation expense	187	186
Bad debt expense (recovery)	436	(70)
Inventory obsolescence reserve (recovery)	(132)	1,524
Gross profit from the sale of used rental equipment	(2,165)	(494)
Gain on disposal of property, plant and equipment		(16)
Realized loss on short-term investments	36
Effects of changes in operating assets and liabilities:
Trade accounts and notes receivable	(2,210)	(6,390)
Inventories	7,734	(4,541)
Other current assets	3,780	(340)
Accounts payable	2,508	6,462
Accrued expenses and other	(4,475)	(2,083)
Deferred revenue	341	1,761
Income tax payable	3,184	1,690
Net cash provided by operating activities	20,079	7,121
Cash flows from investing activities:
Purchase of property and equipment	(792)	(844)
Proceeds from sale of property and equipment		1
Investment in rental equipment	(16,437)	(943)
Proceeds from sale of used rental equipment	3,577	598
Purchase of short-term investments	(675)
Proceeds from sale of short-term investments	625
Net cash used in investing activities	(13,702)	(1,188)
Cash flows from financing activities:
Principal payments on mortgage loans		(7,700)
Excess tax benefit from share-based compensation	(3)	146
Proceeds from exercise of stock options and other	79	92
Net cash provided by (used in) financing activities	76	(7,462)
Effect of exchange rate changes on cash	1	39
Increase (decrease) in cash and cash equivalents	6,454	(1,490)
Cash and cash equivalents, beginning of period	31,388	33,453
Cash and cash equivalents, end of period	$ 37,842	$ 31,963