Business Acquisition - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 17, 2016	Sep. 30, 2016	Dec. 31, 2015	Aug. 05, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill		$ 66,351	$ 65,982		$ 33,798
TAS Commercial Concrete
Business Acquisition [Line Items]
Accounts receivable				$ 54,987
Costs and estimated earnings in excess of billings on uncompleted contracts				4,372
Prepaid expenses and other current assets				828
Fixed assets, net				15,720
Investment in GLM Concrete Services, LLC				76
Goodwill				33,817
Other intangible assets				33,650
Accounts payable				(18,458)
Accrued expenses and other current liabilities				(13,015)
Total Acquisition Consideration At August 5, 2015				$ 111,977
Working Capital Adjustment	$ (1,633)
Adjustment	385
Total Acquisition Consideration	$ 110,729