CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income	$ 14,415	$ 16,486
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,838	8,521
Stock-based compensation	4,467	4,809
Amortization of premium on marketable securities and deferred financing costs	235	122
Earnings of equity method investments	(1,772)	(2,180)
Deferred income tax benefit	(7,682)	(689)
Other gains on disposals of assets	6
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(13,826)	(16,157)
Inventories	(12,260)	(5,518)
Prepaid expenses and other assets	1,029	3,285
Accounts payable	7,932	4,449
Deferred revenue	6,385	1,376
Accrued warranty and retrofit costs	572	87
Accrued compensation and tax withholdings	(13,842)	(11,145)
Accrued restructuring costs	(181)	(592)
Accrued expenses and other liabilities	8,948	362
Net cash provided by operating activities	6,264	3,216
Cash flows from investing activities
Purchases of property, plant and equipment	(3,560)	(2,700)
Purchases of marketable securities	(1,290)	(26,875)
Sales of marketable securities	48,904
Maturities of marketable securities	2,557	100
Acquisitions, net of cash acquired	(445,210)	(65,074)
Proceeds from sales of property, plant and equipment		200
Net cash used in investing activities	(398,599)	(94,349)
Cash flows from financing activities
Proceeds from term loan	340,540	197,554
Payment of deferred financing costs		(318)
Repayment of term loan	(1,789)
Payment of capital lease	(121)
Common stock dividends paid	(7,208)	(7,057)
Net cash provided by financing activities	331,422	190,179
Effects of exchange rate changes on cash and cash equivalents	(1,004)	1,671
Net increase (decrease) in cash and cash equivalents	(61,917)	100,717
Cash and cash equivalents, beginning of period	197,708	101,622
Cash and cash equivalents, end of period	135,791	202,339
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property, plant and equipment included in accounts payable	1,717	865
Deferred financing costs included in accounts payable	$ 1,750	$ 143