CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income	$ 43,320	$ 26,028
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	12,883	15,746
Stock-based compensation	7,891	6,710
Amortization of premium on marketable securities and deferred financing costs	56	56
Deferred income taxes	(3,084)	(4,960)
(Gain) loss on disposals of assets	(95)	1
Adjustment to the gain on divestiture, net of tax		948
Changes in operating assets and liabilities, net of acquisitions and divestiture:
Accounts receivable	1,121	(4,504)
Inventories	(32,150)	(6,307)
Prepaid expenses and other assets	(19,647)	28,945
Accounts payable	(2,219)	5,727
Deferred revenue	4,056	3,186
Accrued warranty and retrofit costs	(103)	(185)
Accrued compensation and tax withholdings	(5,371)	(12,307)
Accrued restructuring costs	(154)	(75)
Accrued expenses and other liabilities	9,114	(15,279)
Net cash provided by operating activities	15,618	43,730
Cash flows from investing activities
Purchases of property, plant and equipment	(18,409)	(15,227)
Purchases of marketable securities	(46)	(4)
Sales of marketable securities	30
Acquisitions, net of cash acquired		(15,061)
Net cash used in investing activities	(18,425)	(30,292)
Cash flows from financing activities
Principal repayments of finance lease obligations	(186)	(319)
Principal payments on debt		(414)
Common stock dividends paid	(7,494)	(7,424)
Net cash used in financing activities	(7,680)	(8,157)
Effects of exchange rate changes on cash and cash equivalents	(1,804)	11,250
Net (decrease) increase in cash, cash equivalents and restricted cash	(12,291)	16,531
Cash, cash equivalents and restricted cash, beginning of period	285,333	302,526
Cash, cash equivalents and restricted cash, end of period	273,042	319,057
Supplemental disclosures:
Cash paid for interest	333	370
Cash paid for income taxes, net	$ 10,911	$ 3,697