REVENUE RECOGNITION - Impact of Topic 606 on Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 28, 2019	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unbilled contract revenue	$ 7,305	$ 0
Inventories	44,889	34,126
Deferred income taxes	7,999	8,855
Accumulated deficit	(17,069)	$ (20,463)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unbilled contract revenue	0
Inventories	51,086
Deferred income taxes	8,242
Accumulated deficit	(17,934)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] \| ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unbilled contract revenue	7,305
Inventories	(6,197)
Accumulated deficit	$ 865

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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