CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net income	$ 25,090	$ 106,112
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,429	27,621
Stock-based compensation	15,172	14,999
Amortization of premium on marketable securities and deferred financing costs	766	565
Earnings of equity method investments	(4,876)	(4,931)
Loss recovery on insurance claim		(1,103)
Deferred income tax benefit	(9,207)	(48,274)
Loss on extinguishment of debt	9,051
Other gains on disposals of assets	156
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(6,456)	(32,887)
Inventories	(6,431)	(21,647)
Prepaid expenses and other assets	2,109	(4,395)
Accounts payable	(6,761)	16,656
Deferred revenue	4,959	487
Accrued warranty and retrofit costs	1,022	(192)
Accrued compensation and tax withholdings	(9,404)	(1,252)
Accrued restructuring costs	(361)	(1,523)
Proceeds from recovery on insurance claim	1,082
Accrued expenses and other liabilities	1,901	(7,478)
Net cash provided by operating activities	58,241	42,758
Cash flows from investing activities
Purchases of property, plant and equipment	(15,548)	(9,320)
Purchases of marketable securities	(1,290)	(58,312)
Sales of marketable securities	48,904
Maturities of marketable securities	2,557	8,450
Acquisitions, net of cash acquired	(442,704)	(82,977)
Proceeds from sales of property, plant and equipment		200
Net cash used in investing activities	(408,081)	(141,959)
Cash flows from financing activities
Proceeds from term loans, net of discount	686,386	197,554
Proceeds from issuance of common stock	1,548	1,395
Payments of financing costs	(687)	(318)
Principal payments on debt	(354,940)	(1,000)
Payments of capital lease	(849)
Common stock dividends paid	(21,658)	(21,202)
Net cash provided by financing activities	309,800	176,429
Effects of exchange rate changes on cash and cash equivalents	(816)	526
Net increase (decrease) in cash and cash equivalents	(40,856)	77,754
Cash and cash equivalents, beginning of period	197,708	101,622
Cash and cash equivalents, end of period	156,852	179,376
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property, plant and equipment included in accounts payable	$ 1,847	$ 1,418