CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities
Net (loss) income	$ (69,476)	$ 14,221	$ 31,522
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	28,046	25,160	23,459
Impairment of intangible assets	0	0	398
Impairment of other assets	807	0	2,621
Stock-based compensation	11,737	12,159	10,912
Amortization of premium on marketable securities and deferred financing costs	339	1,193	1,255
Undistributed (earnings) losses of equity method investments	(2,380)	164	(1,235)
Deferred income tax provision (benefit)	70,273	(2,173)	(1,779)
Loss on write-downs of assets held for sale	0	1,944	0
Pension settlement	0	232	0
Gain on disposal of businesses	0	(85)	(27,444)
(Gain) loss on disposal of long-lived assets	(41)	0	13
Changes in operating assets and liabilities, net of acquisitions and disposals:
Accounts receivable	(1,796)	(5,134)	12,098
Inventories	8,565	(5,919)	9,598
Prepaid expenses and other current assets	(428)	(2,875)	(12,325)
Accounts payable	(5,143)	8,358	(11,924)
Deferred revenue	(3,290)	(6,779)	5,900
Accrued warranty and retrofit costs	290	(407)	(1,102)
Accrued compensation and tax withholdings	(3,234)	(1,148)	6,783
Accrued restructuring costs	3,860	(1,247)	2,161
Accrued pension costs	(811)	812	997
Accrued expenses and other current liabilities	2,229	5,251	1,873
Net cash provided by operating activities	39,547	43,727	53,781
Cash flows from investing activities
Purchases of property, plant and equipment	(12,848)	(16,146)	(5,518)
Purchases of marketable securities	(12,901)	(87,333)	(174,287)
Sales and maturities of marketable securities	139,388	104,008	112,085
Proceeds from divestitures	0	0	85,369
Disbursement for a loan receivable	1,821	0	0
Proceeds from liquidation of a joint venture	0	1,778	0
Acquisitions, net of cash acquired	(125,248)	(14,450)	(35,625)
Decrease in restricted cash	0	0	177
Purchases of other investments	(250)	(5,500)	0
Proceeds from sales of property, plant and equipment	2,806	6	0
Net cash used in investing activities	(10,874)	(17,637)	(17,799)
Cash flows from financing activities
Proceeds from line of credit	366	0	0
Proceeds from issuance of common stock	1,888	1,807	1,838
Principal repayments of capital lease obligations	0	0	(239)
Payment of deferred financing costs	(708)	0	0
Acquisitions of noncontrolling interest	0	0	(3,189)
Repayment of debt assumed in business acquisition	0	(8,829)	0
Common stock dividends paid	(27,503)	(26,992)	(22,875)
Net cash used in financing activities	(25,957)	(34,014)	(24,465)
Effects of exchange rate changes on cash and cash equivalents	1,648	(5,468)	(374)
Net increase (decrease) in cash and cash equivalents	4,364	(13,392)	11,143
Cash and cash equivalents, beginning of year	80,722	94,114	82,971
Cash and cash equivalents, end of year	85,086	80,722	94,114
Supplemental disclosures:
Cash paid for interest	114	395	202
Cash paid for income taxes, net	4,930	3,883	1,084
Supplemental disclosure of non-cash investing and financing activities:
Acquisition of buildings and land through capital lease	0	0	8,537
Derecognition of a capital lease obligation and the related assets	$ 0	$ 7,804	$ 0