Accrued Expenses and Other Current Liabilities (Severance and Restructuring Accruals) (Narrative) (Details)		1 Months Ended					12 Months Ended
	Jun. 07, 2016 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 employee	Nov. 30, 2016 employee	May 31, 2016 employee	Dec. 31, 2015 USD ($)	Sep. 30, 2018 employee	Sep. 30, 2017 USD ($) employee	Sep. 30, 2016 USD ($)
Payables and Accruals [Line Items]
Payments to terminate lease agreement									$ 200,000
Employee Severance [Member]
Payables and Accruals [Line Items]
Restructuring costs								$ 400,000
Chief Financial Officer [Member]
Payables and Accruals [Line Items]
Continuation of base salary period	448 days
Outplacement services, period	1 year
Outplacement services, value	$ 15,000
Estimated charge related to separation agreement									400,000
Discontinued Operations, Disposed of by Sale [Member]
Payables and Accruals [Line Items]
Payments to terminate lease agreement						$ 200,000
Gain on lease termination									300,000
Satellite Communications Assembly Operations [Member] | Employee Severance [Member]
Payables and Accruals [Line Items]
Number of positions eliminated | employee				5	30
Restructuring costs								$ 200,000	$ 300,000
Ivyland, Pennsylvania Location Closure [Member] | Employee Severance [Member]
Payables and Accruals [Line Items]
Restructuring costs		$ 300,000
Water Fabrication Lab [Member]
Payables and Accruals [Line Items]
Number of positions eliminated | employee			14
Water Fabrication Lab [Member] | Employee Severance [Member]
Payables and Accruals [Line Items]
Number of positions eliminated | employee								72
Restructuring costs								$ 100,000
Workforce Reduction [Member] | Employee Severance [Member]
Payables and Accruals [Line Items]
Number of positions eliminated | employee								6
Restructuring costs								$ 400,000
New Manufacturing Facility in China [Member] | Employee Severance [Member]
Payables and Accruals [Line Items]
Number of positions eliminated | employee			265
Restructuring costs								$ 500,000
Scenario, Forecast [Member] | Ivyland, Pennsylvania Location Closure [Member] | Employee Severance [Member]
Payables and Accruals [Line Items]
Number of positions eliminated | employee							11