Intangible Assets - Finite Lived Intangible Assets (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	$ 48,570,000	$ 34,370,000	$ 49,370,000
Total amortized intangible assets, Accumulated Amortization	(17,551,000)	(12,720,000)	(15,319,000)
Total amortized intangible assets, Net Value	31,019,000	21,650,000	34,051,000
Amortization expense	2,200,000	1,100,000
Future amortization expense, Remainder of Fiscal Year	7,200,000
Future amortization expense, Year One	2,400,000
Future amortization expense, Year Two	1,900,000
Future amortization expense, Year Three	1,800,000
Future amortization expense, Year Four	1,700,000
Future amortization expense, after Year Four	16,000,000
Permits [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	29,713,000	29,713,000	29,713,000
Total amortized intangible assets, Accumulated Amortization	(11,149,000)	(8,589,000)	(10,869,000)
Total amortized intangible assets, Net Value	18,564,000	21,124,000	18,844,000
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	4,398,000	2,198,000	4,698,000
Total amortized intangible assets, Accumulated Amortization	(2,271,000)	(2,000,000)	(2,170,000)
Total amortized intangible assets, Net Value	2,127,000	198,000	2,528,000
Covenants not to compete [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	1,588,000	1,588,000	1,588,000
Total amortized intangible assets, Accumulated Amortization	(1,549,000)	(1,510,000)	(1,546,000)
Total amortized intangible assets, Net Value	39,000	78,000	42,000
Order or Production Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	7,900,000		7,900,000
Total amortized intangible assets, Accumulated Amortization	(1,707,000)		0
Total amortized intangible assets, Net Value	6,193,000		8,400,000
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	4,100,000		4,100,000
Total amortized intangible assets, Accumulated Amortization	(108,000)		0
Total amortized intangible assets, Net Value	3,992,000		4,100,000
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value	871,000	871,000	871,000
Total amortized intangible assets, Accumulated Amortization	(767,000)	(621,000)	(734,000)
Total amortized intangible assets, Net Value	104,000	250,000	137,000
Scenario, Previously Reported [Member] | Order or Production Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Total amortized intangible assets, Gross Value			$ 8,400,000