Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Sep. 30, 2017 USD ($) Customer instrument Segment shares	Sep. 30, 2016 USD ($) Customer Segment shares
Accounting Policies [Line Items]
Number of operating segments | Segment	1	1
Allowance for doubtful accounts	$ 330,000	$ 706,000
Accounts receivable, written off	461,000	581,000
Bad debt expense	$ 77,000	$ 359,000
Percentage of inventory estimated using LIFO method	38.00%	44.00%
Reserve for obsolete and excess inventory	$ 3,859,000	$ 3,308,000
Depreciation expense	7,820,000	8,173,000
Impairment of assets to be disposed of	4,786,000
Impairment of machinery and equipment		0
Impairment of intangible assets	2,289,000	0
ERP impairment charges	174,000
Cork, Ireland facility, accumulated depreciation	$ 51,661,000	$ 50,079,000
Restricted shares included in calculation of net loss per share (in shares) | shares	93,000	32,000
Research and development expense	$ 0	$ 0
Revolver	$ 18,557,000	12,751,000
Interest Rate Swap
Accounting Policies [Line Items]
Number of interest rate swaps (instrument) | instrument	1
Interest rate swap agreement amount	$ 4,059,000
Derivative asset	$ 4,000
Derivative liability		$ 30,000
Restricted Stock
Accounting Policies [Line Items]
Restricted shares included in calculation of net loss per share (in shares) | shares	0	0
Subsidiaries
Accounting Policies [Line Items]
Rental income, quarterly installment	$ 103,000
Cork, Ireland facility, carrying value	1,447,000	$ 1,496,000
Cork, Ireland facility, accumulated depreciation		1,437,000
Rental income	$ 413,000	$ 413,000
Minimum
Accounting Policies [Line Items]
Intangible assets amortized over useful lives (in years)	1 year
Maximum
Accounting Policies [Line Items]
Intangible assets amortized over useful lives (in years)	10 years
Building and Building Improvements | Minimum
Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)	5 years
Building and Building Improvements | Maximum
Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)	40 years
Machinery and Equipment
Accounting Policies [Line Items]
Impairment of machinery and equipment	$ 2,497,000
Machinery and Equipment | Minimum
Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)	3 years
Machinery and Equipment | Maximum
Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)	20 years
Computer Software | Minimum
Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)	3 years
Computer Software | Maximum
Accounting Policies [Line Items]
Property, plant and equipment, useful life (in years)	7 years
Building, Machinery, and Equipment | Subsidiaries
Accounting Policies [Line Items]
Cork, Ireland facility, carrying value	$ 1,077,000
Customer Concentration Risk | Sales Revenue, Net
Accounting Policies [Line Items]
Percentage of concentration risk	22.00%	21.00%
Number of major customers | Customer	2	2
Customer Concentration Risk | Sales Revenue, Net | Total Customers And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	35.00%	46.00%
Number of major customers | Customer	3	4
Customer Concentration Risk | Sales Revenue, Net | Major Customer One And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	13.00%	12.00%
Customer Concentration Risk | Sales Revenue, Net | Major Customer Two And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	11.00%	12.00%
Customer Concentration Risk | Sales Revenue, Net | Major Customer Three And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	11.00%	11.00%
Customer Concentration Risk | Sales Revenue, Net | Major Customer Four And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk		11.00%
Customer Concentration Risk | Accounts Receivable
Accounting Policies [Line Items]
Number of major customers | Customer	1	2
Customer Concentration Risk | Accounts Receivable | Total Customers And Their Subcontractors
Accounting Policies [Line Items]
Number of major customers | Customer	3	4
Customer Concentration Risk | Accounts Receivable | Major Customer One And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	13.00%	15.00%
Customer Concentration Risk | Accounts Receivable | Major Customer Two And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	10.00%	13.00%
Customer Concentration Risk | Accounts Receivable | Major Customer Three And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk	10.00%	12.00%
Customer Concentration Risk | Accounts Receivable | Major Customer Four And Their Subcontractors
Accounting Policies [Line Items]
Percentage of concentration risk		11.00%
Customer Concentration Risk | Accounts Receivable | Customer One
Accounting Policies [Line Items]
Percentage of concentration risk	10.00%	14.00%
Customer Concentration Risk | Accounts Receivable | Customer Two
Accounting Policies [Line Items]
Percentage of concentration risk		11.00%