CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Statement of Financial Position [Abstract]
Accounts receivable, net allowances	$ 6,183	$ 5,966
Contract costs, net of progress payments	$ 4,808	$ 4,407

The amount of the offset related to government or other customer advances received on a contract when the expected advances will be applied in payment to those particular charges of the receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 912
-SubTopic 210
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68069949&loc=d3e52987-109388

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 912
-SubTopic 210
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68071014&loc=d3e53318-109389

Name:	us-gaap_CustomerAdvancesAndProgressPaymentsForLongTermContractsOrPrograms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant