Segment Information (Details 1) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 573,495	$ 524,925
T&D [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	235,548	204,309
C&I [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	125,696	92,939
Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 212,251	$ 227,677