Contingencies (Details Textual) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Claims related to unapproved change orders	$ 15.0	$ 11.0

The total amount of accounts receivable from customers under long-term contracts or programs associated with unapproved change orders or other similar items subject to uncertainty concerning their determination or ultimate realization.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(c)(4))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AccountsReceivableUnapprovedContractClaims
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant