CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 24,176	$ 22,013
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income tax expense	248	458
Depreciation	3,474	1,994
Amortization		60
Accretion of discounts on short-term-investments		87
Stock-based compensation	810	250
Bad debt expense	347	269
Inventory obsolescence recovery	904	(550)
Gross profit from the sale of used rental equipment	(5,331)	(6,519)
(Gain) loss on disposal of property, plant and equipment	(31)	19
Realized gain on short-term investments		(1)
Effects of changes in operating assets and liabilities:
Trade accounts and notes receivable	(2,243)	(5,981)
Inventories	13,717	(13,704)
Costs and estimated earnings in excess of billings	9,266	(6,325)
Other current assets	(4,157)	(3,823)
Prepaid income taxes	(2,031)	(1,231)
Accounts payable	(1,086)	154
Accrued expenses and other	(2,146)	152
Deferred revenue	4,496	2,112
Income taxes payable	12,321	8,454
Net cash provided by (used in) operating activities	52,734	(2,112)
Cash flows from investing activities:
Purchase of property, plant and equipment	(1,382)	(6,494)
Investment in rental equipment	(17,717)	(11,419)
Proceeds from sale of used rental equipment	8,092	12,408
Purchases of short-term investments		(702)
Proceeds from the sale of short-term investments		900
Net cash used in investing activities	(11,007)	(5,307)
Cash flows from financing activities:
Principal payments on debt arrangements	(931)
Excess tax benefit from stock-based compensation	661	1,092
Proceeds from exercise of stock options and other	212	461
Net cash provided by (used in) financing activities	(58)	1,553
Effect of exchange rate changes on cash	(2)
Increase (decrease) in cash and cash equivalents	41,667	(5,866)
Cash and cash equivalents, beginning of period	2,726	50,752
Cash and cash equivalents, end of period	$ 44,393	$ 44,886