Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Line Items]
Amortization of Intangible Assets	$ 499	$ 886	$ 571
Western Pacific Enterprises [Member] | High Country Line Construction Inc [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Line Items]
Goodwill, Period Increase (Decrease)	$ 200
Western Pacific Enterprises [Member] | Maximum [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years 6 months
Trade Names [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Line Items]
Estimated useful life	15 years
Customer Relationships [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Line Items]
Estimated useful life	12 years