Business Segments (Details) $ in Millions	12 Months Ended
Sep. 30, 2016 USD ($) segment	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Business segments
Number of business segments \| segment	1
Outside the United States
Geographic Data
Net sales from outside the United States \| $	$ 8.2	$ 6.6	$ 12.0
FPDS \| Net sales
Business segments
Sales percentage	95.00%	98.00%	88.00%
Air data systems and components \| Net sales
Business segments
Sales percentage	5.00%	2.00%	12.00%
EDC services \| Net sales
Business segments
Sales percentage	4.00%	27.00%	32.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13537-108611

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Data Type:	num:percentItemType
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Period Type:	duration