CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net income (loss)	$ 13,871	$ (4,648)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	6,752	6,445
Gain on settlement of equity method investment	(1,847)	0
Stock-based compensation	2,498	4,714
Amortization of premium on marketable securities and deferred financing costs	79	274
Undistributed earnings of equity method investments	(1,942)	(159)
Deferred income tax benefit	(421)	(3,797)
Gain on disposal of long-lived assets	(109)	0
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(11,137)	218
Inventories	(2,930)	119
Prepaid expenses and other current assets	(3,516)	(1,697)
Accounts payable	13,040	(7,639)
Deferred revenue	10,737	8,872
Accrued warranty and retrofit costs	(4)	(305)
Accrued compensation and tax withholdings	(6,884)	(10,059)
Accrued restructuring costs	(2,538)	(407)
Accrued expenses and other current liabilities	3,061	(4,308)
Net cash provided by (used in) operating activities	18,710	(12,377)
Cash flows from investing activities
Purchases of property, plant and equipment	(3,768)	(2,486)
Purchases of marketable securities	0	(12,901)
Sales and maturities of marketable securities	0	135,873
Disbursement for a loan receivable	0	(300)
Acquisitions, net of cash acquired	(5,346)	(125,498)
Purchases of other investments	(170)	0
Net cash used in investing activities	(9,284)	(5,312)
Cash flows from financing activities
Payment of deferred financing costs	(27)	0
Common stock dividends paid	(6,966)	(6,844)
Net cash used in financing activities	(6,993)	(6,844)
Effects of exchange rate changes on cash and cash equivalents	(4,574)	(617)
Net decrease in cash and cash equivalents	(2,141)	(25,150)
Cash and cash equivalents, beginning of period	85,086	80,722
Cash and cash equivalents, end of period	82,945	55,572
Supplemental disclosure of non-cash investing activities:
Purchases of property, plant and equipment included in accounts payable	424	955
Fair value of non-cash consideration for the acquisition of Cool Lab, LLC	$ 10,348	$ 0