Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income (loss)	$ (32,641,000)	$ 36,911,000	$ 69,557,000
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred income tax expense (benefit)	(943,000)	818,000	(523,000)
Depreciation and amortization	19,547,000	17,774,000	12,229,000
Goodwill impairment	1,843,000
Accretion of discounts on short-term-investments	225,000	49,000	162,000
Stock-based compensation expense	4,539,000	4,119,000	544,000
Bad debt expense	2,147,000	833,000	457,000
Inventory obsolescence expense	3,887,000	2,617,000	187,000
Gross profit from sale of used rental equipment	(3,208,000)	(9,031,000)	(13,627,000)
Loss (gain) on disposal of property, plant and equipment	26,000	(64,000)	301,000
Realized loss (gain) on short-term investments	7,000	0	(19,000)
Excess tax expense from stock-based compensation	(1,083,000)
Effects of changes in operating assets and liabilities:
Trade accounts and notes receivable	7,088,000	25,605,000	(33,717,000)
Income tax receivable	(14,799,000)	(2,639,000)	(137,000)
Inventories	9,661,000	(10,452,000)	(73,357,000)
Costs and estimated earnings in excess of billings		12,400,000	(12,400,000)
Prepaid expenses and other current assets	997,000	998,000	(321,000)
Prepaid income taxes	1,753,000	353,000	(722,000)
Accounts payable trade	(834,000)	(11,756,000)	(442,000)
Accrued expenses and other	(6,004,000)	(3,435,000)	3,324,000
Deferred revenue	(3,567,000)	2,685,000	(7,541,000)
Income taxes payable	(10,000)	(135,000)	(1,116,000)
Net cash provided by (used in) operating activities	(11,369,000)	67,650,000	(57,161,000)
Cash flows from investing activities:
Purchase of property, plant and equipment	(2,189,000)	(6,792,000)	(19,384,000)
Proceeds from the sale of property, plant and equipment		27,000
Investment in rental equipment	(3,973,000)	(26,719,000)	(22,275,000)
Proceeds from the sale of used rental equipment	4,278,000	16,390,000	25,497,000
Purchases of short-term investments	(6,306,000)	(21,610,000)	(1,587,000)
Proceeds from the sale of short-term investments	7,902,000	2,000,000	21,139,000
Net cash provided by (used in) investing activities	(288,000)	(36,704,000)	3,390,000
Cash flows from financing activities:
Net (payments) borrowings under line of credit		(931,000)	931,000
Excess tax benefits from stock-based compensation		178,000	3,390,000
Proceeds from exercise of stock options and other		424,000	1,419,000
Net cash provided by (used in) financing activities		(329,000)	5,740,000
Effect of exchange rate changes on cash	614,000	14,000	5,000
Increase (decrease) in cash and cash equivalents	(11,043,000)	30,631,000	(48,026,000)
Cash and cash equivalents, beginning of fiscal year	33,357,000	2,726,000	50,752,000
Cash and cash equivalents, end of fiscal year	$ 22,314,000	$ 33,357,000	$ 2,726,000