Intangible Assets - Finite Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets, Net [Abstract]
Total amortized intangible assets, Gross Value	$ 33,809	$ 48,570
Total amortized intangible assets, Accumulated Amortization	(15,911)	(28,636)
Total amortized intangible assets, Net Value	17,898	19,934
Amortization expense	2,000	2,200	$ 2,300
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Future amortization expense, 2016	1,700
Future amortization expense, 2017	1,700
Future amortization expense, 2018	1,700
Future amortization expense, 2019	1,600
Future amortization expense, thereafter	11,100
Permits [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Total amortized intangible assets, Gross Value	25,959	29,713
Total amortized intangible assets, Accumulated Amortization	(11,514)	(14,239)
Total amortized intangible assets, Net Value	14,445	15,474
Customer lists [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Total amortized intangible assets, Gross Value	2,200	4,398
Total amortized intangible assets, Accumulated Amortization	(1,174)	(3,078)
Total amortized intangible assets, Net Value	1,026	1,320
Covenants not to compete [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Total amortized intangible assets, Gross Value	50	2,459
Total amortized intangible assets, Accumulated Amortization	(24)	(2,430)
Total amortized intangible assets, Net Value	26	29
Order or Production Backlog [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Total amortized intangible assets, Gross Value	1,500	7,900
Total amortized intangible assets, Accumulated Amortization	(1,472)	(7,594)
Total amortized intangible assets, Net Value	28	306
Trade Names [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Total amortized intangible assets, Gross Value	4,100	4,100
Total amortized intangible assets, Accumulated Amortization	(1,727)	(1,295)
Total amortized intangible assets, Net Value	$ 2,373	$ 2,805