SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Deferred tax valuation allowance (deducted from net deferred tax assets)
Activity in valuation and qualifying accounts
Balance at beginning of period	$ 39,337	$ 54,379	$ 44,257
Charged (credited) to expense	2,572	(15,042)	10,122
Reductions	0	0	0
Balance at end of period	41,909	39,337	54,379
Allowance for doubtful accounts (deducted from accounts receivable)
Activity in valuation and qualifying accounts
Balance at beginning of period	337	668	718
Charged (credited) to expense	178	199	357
Reductions	(224)	(530)	(407)
Balance at end of period	291	337	668
Provision for Inventory allowance (deducted from inventory)
Activity in valuation and qualifying accounts
Balance at beginning of period	503	4,572	3,446
Charged (credited) to expense	331	2,494	10,381
Reductions	(503)	(6,563)	(9,255)
Balance at end of period	$ 331	$ 503	$ 4,572

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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- Definition

Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

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- Definition

Amount of decrease in valuation and qualifying accounts and reserves.

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