CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 38,882	$ 20,116
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income tax expense	1,084	5
Depreciation	5,857	4,810
Amortization	80	120
Accretion of discounts on short-term-investments	160	73
Stock-based compensation	347	376
Bad debt expense	607	604
Inventory obsolescence (recovery) provision	(186)	1,125
Gross profit from the sale of used rental equipment	(9,062)	(7,301)
Loss on disposal of property, plant and equipment	14
Realized (gain) loss on short-term investments	(6)	1
Effects of changes in operating assets and liabilities:
Trade accounts and notes receivable	(21,188)	(13,435)
Inventories	(31,428)	2,068
Costs and estimated earnings in excess of billings	(11,309)
Prepaid expenses and other current assets	(4,710)	3,227
Prepaid income taxes	(2,034)	(2,730)
Accounts payable trade	1,735	6,772
Accrued expenses and other	(2,350)	34
Deferred revenue	(8,461)	4,674
Income taxes payable	(587)	2,680
Net cash provided by (used in) operating activities	(42,555)	23,219
Cash flows from investing activities:
Purchase of property, plant and equipment	(8,244)	(1,672)
Investment in rental equipment	(17,673)	(22,191)
Proceeds from sale of used rental equipment	17,074	12,451
Purchases of short-term investments	(1,587)	(1,025)
Proceeds from the sale of short-term investments	10,672	950
Net cash provided by (used in) investing activities	242	(11,487)
Cash flows from financing activities:
Excess tax benefit from stock-based compensation	2,948	425
Proceeds from exercise of stock options and other	917	605
Net cash provided by financing activities	3,865	1,030
Effect of exchange rate changes on cash	4
Increase (decrease) in cash and cash equivalents	(38,444)	12,762
Cash and cash equivalents, beginning of period	50,752	31,388
Cash and cash equivalents, end of period	$ 12,308	$ 44,150