Goodwill (Tables)

12 Months Ended

Dec. 31, 2016

Goodwill [Abstract]

Schedule of goodwill by reporting segment

The changes in the carrying amount of goodwill by reporting segment during the years ended December 31, 2016 and 2015 are as follows:

	Infrastructure Group			Aggregate and Mining Group			Energy Group		Corporate		Total
Balance, December 31, 2014	$	8,584		$	23,411		$	--	$	--	$	31,995
Purchase price adjustment		--			(178	)		--		--		(178	)
Foreign currency translation		(103	)		(879	)		--		--		(982	)
Balance, December 31, 2015		8,481			22,354			--		--		30,835
Acquisition		--			--			12,632		--		12,632
Foreign currency translation		(33	)		(2,630	)		--		--		(2,663	)
Balance, December 31, 2016	$	8,448		$	19,724		$	12,632	$	--	$	40,804