CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net income	$ 22,184	$ 17,836
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33,079	26,339
Stock-based compensation	8,624	9,717
Amortization of premium on marketable securities and deferred financing costs	94	556
Earnings of equity method investments		(3,041)
Deferred income taxes	(9,477)	(12,472)
Loss on extinguishment of debt		9,051
Other losses on disposals of assets	125	34
Loss on sale of divestiture, net of tax	319
Taxes paid stemming from divestiture	(91,500)
Changes in operating assets and liabilities, net of acquisitions and divestiture:
Accounts receivable	(12,670)	(9,654)
Inventories	(9,094)	(9,992)
Prepaid expenses and other assets	5,374	1,938
Accounts payable	5,807	(6,088)
Deferred revenue	(1,478)	5,410
Accrued warranty and retrofit costs	735	740
Accrued compensation and tax withholdings	(522)	(11,123)
Accrued restructuring costs	(112)	(57)
Proceeds from recovery on insurance claim		886
Accrued expenses and other liabilities	8,455	2,149
Net cash (used in) provided by operating activities	(40,057)	22,229
Cash flows from investing activities
Purchases of property, plant and equipment	(21,170)	(9,676)
Purchases of marketable securities	(10,843)	(1,290)
Sales of marketable securities	2,492	48,904
Maturities of marketable securities	42,226	2,557
Acquisitions, net of cash acquired	(15,743)	(442,704)
Issuance of a note receivable	(1,000)
Net cash used in investing activities	(4,038)	(402,209)
Cash flows from financing activities
Proceeds from term loans, net of discount		686,386
Proceeds from issuance of common stock	2,330	1,548
Payments of financing costs		(687)
Principal payments on debt	(414)	(352,289)
Payments of capital leases	(639)	(487)
Common stock dividends paid	(14,747)	(14,429)
Net cash (used in) provided by financing activities	(13,470)	320,042
Effects of exchange rate changes on cash and cash equivalents	(1,803)	(553)
Net decrease in cash, cash equivalents and restricted cash	(59,368)	(60,491)
Cash, cash equivalents and restricted cash, beginning of period	305,171	197,708
Cash, cash equivalents and restricted cash, end of period	245,803	137,217
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property, plant and equipment included in accounts payable	$ 1,305	$ 1,670