CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net income	$ 88,942	$ 35,880
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	48,684	49,760
Impairment of property, plant and equipment		301
Stock-based compensation	20,277	12,348
Amortization of premium on marketable securities and deferred financing costs	169	177
Deferred income taxes	(10,293)	(9,319)
Other losses on disposals of assets	225	163
Adjustment to the gain on divestiture, net of tax	948	319
Taxes paid stemming from divestiture		(91,500)
Changes in operating assets and liabilities, net of acquisitions and divestiture:
Accounts receivable	(40,286)	(15,719)
Inventories	(32,532)	(17,695)
Prepaid expenses and other assets	4,000	12,554
Accounts payable	23,327	11,032
Deferred revenue	(1,564)	214
Accrued warranty and retrofit costs	(286)	580
Accrued compensation and tax withholdings	(338)	1,928
Accrued restructuring costs	(153)	(609)
Accrued expenses and other liabilities	21,625	(4,347)
Net cash provided by (used in) operating activities	122,745	(13,933)
Cash flows from investing activities
Purchases of property, plant and equipment	(34,606)	(29,685)
Purchases of marketable securities	(100)	(10,843)
Sales of marketable securities	25	2,492
Maturities of marketable securities	25	42,226
Adjustment to proceeds from divestiture - NOT USED IN 10-K	(1,802)
Acquisitions, net of cash acquired	(92,375)	(15,743)
Issuance of a note receivable		(1,000)
Net cash used in by investing activities	(128,833)	(12,553)
Cash flows from financing activities
Proceeds from issuance of common stock	2,583	2,332
Principal payments on debt	(828)	(828)
Payments of finance leases	(915)	(957)
Common stock dividends paid	(22,288)	(22,127)
Net cash used in financing activities	(21,448)	(21,580)
Effects of exchange rate changes on cash and cash equivalents	7,582	3,095
Net decrease in cash, cash equivalents and restricted cash	(19,954)	(44,971)
Cash, cash equivalents and restricted cash, beginning of period	302,526	305,171
Cash, cash equivalents and restricted cash, end of period	282,572	260,200
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property, plant and equipment included in accounts payable	$ 14,516	$ 2,020