Goodwill and Intangible Assets - Goodwill Rollforward (Details) $ in Thousands	9 Months Ended
Jun. 30, 2016 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 17,249
Acquisitions	22,957
Divestitures	577
Goodwill, Ending Balance	39,629
Residential [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	8,631
Acquisitions	0
Divestitures	0
Goodwill, Ending Balance	8,631
Commercial & Industrial [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	0
Acquisitions	3,676
Goodwill, Ending Balance	3,676
Infrastructure Solutions [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	8,618
Acquisitions	19,281
Divestitures	577
Goodwill, Ending Balance	$ 27,322

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

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

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

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Balance Type:	credit
Period Type:	duration

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- Details

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