Business Combination (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended							12 Months Ended	0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2014 Infrastructure Solutions [Member]	Sep. 30, 2014 Residential [Member]	Sep. 30, 2013 Residential [Member]	Sep. 30, 2012 Residential [Member]	Sep. 30, 2013 Business Acquisition Acro [Member]	Feb. 15, 2014 Business Acquisition Acro [Member] Residential [Member]	Sep. 30, 2014 Business Acquisition Acro [Member] Residential [Member]	Feb. 15, 2013 Business Acquisition Acro [Member] Residential [Member]	Sep. 13, 2013 Business Acquistion Miscor [Member] Infrastructure Solutions [Member]	Sep. 30, 2014 Business Acquistion Miscor [Member] Infrastructure Solutions [Member]	Sep. 30, 2014 Business Acquistion Miscor [Member] Deferred Tax Liability [Member] Infrastructure Solutions [Member]	Sep. 30, 2014 Business Acquistion Miscor [Member] Work In Process Inventory [Member]	Sep. 30, 2014 Business Acquistion Miscor [Member] Current Liabilities [Member]
Business Acquisition [Line Items]
Name of Acquired Business										Acro Group			MISCOR Group, Ltd.
Description of Acquired Business										sale, installation, and third-party financing of residential solar equipment			provider of maintenance and repair services including engine parts and components to the industrial and rail service industries.
Date of Acquisition										Feb. 15, 2013			Sep. 13, 2013
Total Consideration Transferred									$ 4,798
Goodwill	14,993	13,924	4,446		8,631	8,631	4,446				4,185		6,362
Contingent Consideration											665
Gain on Contingent Consideration								570		95
Percent Of Acquiree Under Common Control Prior to Acquisition												49.00%
IES Shares provided in MISCOR consideration				2,795,577
Value of IES Shares provided in MISCOR consideration				11,853
Cash Purchase Consideration	0	5,155	0									4,364
Change In Accounting Estimate Description														is the result of the completion of our analysis of the tax basis of the acquired property, plant and equipment, which resulted in the recording of an additional deferred tax liability	we completed our valuation of the acquired inventory, resulting in a $311 reduction in the estimated value previously attributed to work in process inventory	We also identified additional current liabilities of $198, resulting in a further increase to goodwill
Goodwill Purchase Accounting Adjustments	$ 1,069				$ 0								$ 1,069	$ 560	$ 311	$ 198