UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ (3,083)	$ 22,231
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,492	6,696
Provision for doubtful accounts	28	46
Share-based compensation expense	5,861	2,913
Deemed repatriation transition tax	24,641	0
Deferred income tax expense	13,465	1,354
Tax benefit from share-based compensation expense	(2,806)	0
Non-cash foreign exchange (gain)	(657)	(922)
(Gain) on disposal of property, plant and equipment	0	(5)
Other	2,545	919
Changes in operating assets and liabilities:
Accounts receivable	(4,733)	(7,879)
Inventories	(1,669)	(1,725)
Prepaid expenses and other assets	(2,190)	(368)
Accounts payable	(2,847)	2,734
Accrued expenses, income taxes payable and other liabilities	(4,429)	(869)
Net cash provided by operating activities	30,618	25,125
Cash flows from investing activities:
Additions to property, plant and equipment	(4,175)	(4,937)
Proceeds from the sale of property, plant and equipment	0	5
Purchases of available-for-sale securities	(50,174)	0
Proceeds from the sale and maturities of available-for-sale securities	1,851	0
Net cash used in investing activities	(52,498)	(4,932)
Cash flows from financing activities:
Repayment of long-term debt	(3,281)	0
Repurchases of common stock	(4,741)	(3,002)
Net proceeds from issuance of stock	6,464	12,489
Dividends paid	(5,057)	(4,431)
Tax benefits associated with share-based compensation expense	0	2,544
Net cash provided by (used in) financing activities	(6,615)	7,600
Effect of exchange rate changes on cash	7,835	(9,558)
Increase (decrease) in cash and cash equivalents	(20,660)	18,235
Cash and cash equivalents at beginning of period	397,890	287,479
Cash and cash equivalents at end of period	377,230	305,714
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property, plant and equipment in accrued liabilities and accounts payable at the end of the period	$ 1,539	$ 2,229