CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net (loss) income	$ (68,577)	$ 142,828	$ 39,215
Adjustments to reconcile Net (loss) income to net cash provided by operating activities:
Impairment charges	230,392	2,314	67,372
Depreciation and amortization	132,170	127,737	98,592
Deferred income tax benefit	(41,347)	(11,267)	(27,150)
Share-based compensation expense	19,678	16,396	18,227
Amortization of terminated interest rate swap contract	9,287	0	0
Amortization of debt issuance costs	3,152	3,123	2,884
Loss (gain) on disposal of assets	1,374	(71)	(36)
Non-cash foreign exchange loss (gain)	406	(266)	839
Accretion and adjustment on Asset Retirement Obligations	295	599	530
Non-cash charge on inventory step up of acquired inventory sold	0	0	14,869
Other	(1,047)	(796)	(930)
Changes in operating assets and liabilities:
Accounts receivable	(13,429)	13,075	(6,156)
Inventories	(13,023)	(12,337)	(20,993)
Prepaid expenses and other assets	(6,576)	8,645	6,830
Accounts payable	3,586	(2,861)	1,163
Accrued expenses and other liabilities	14,272	165	(20,275)
Net cash provided by operating activities	270,613	287,284	174,981
Cash flows from investing activities:
Acquisition of a business, net of cash acquired	(126,877)	0	(1,182,187)
Additions to property, plant and equipment	(42,103)	(125,839)	(55,972)
Proceeds from the sale of assets	2,620	1,587	1,224
Cash settlement of life insurance policy	0	0	3,959
Net cash used in investing activities	(166,360)	(124,252)	(1,232,976)
Cash flows from financing activities:
Repurchases of common stock under Share Repurchase Program	(120,027)	(35,009)	(10,002)
Dividends paid	(53,015)	(50,383)	(46,324)
Proceeds from issuance of stock	13,388	14,427	17,210
Repayment of long-term debt	(7,988)	(23,313)	(105,326)
Repurchases of common stock withheld for taxes	(5,560)	(3,229)	(4,718)
Debt issuance costs	(1,898)	0	(18,745)
Proceeds from issuance of long-term debt	0	0	1,062,337
Proceeds from revolving line of credit	0	150,000	0
Repayment on revolving line of credit	0	(150,000)	0
Other financing activities	(236)	(149)	0
Net cash (used in) provided by financing activities	(175,336)	(97,656)	894,432
Effect of exchange rate changes on cash	(292)	3,483	(863)
(Decrease) increase in cash and cash equivalents	(71,375)	68,859	(164,426)
Cash and cash equivalents at beginning of year	257,354	188,495	352,921
Cash and cash equivalents at end of year	185,979	257,354	188,495
Supplemental disclosure of cash flow information:
Cash paid for income taxes (net of refunds received)	39,389	44,535	35,432
Cash paid for interest	28,920	45,281	39,181
Purchases of property, plant and equipment in accrued liabilities and accounts payable at the end of the period	5,009	5,365	8,690
Cash paid during the period for lease liabilities	8,274	7,554	0
Right of use asset obtained in exchange for lease liabilities	3,600	7,435	0
KMG Chemicals, Inc.
Supplemental disclosure of cash flow information:
Equity consideration related to the acquisition of KMG Chemicals, Inc	$ 0	$ 0	$ 331,048