Revisions in Estimates (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Change in Accounting Estimate [Line Items]
Gross Profit	$ 21,408,000	$ 30,058,000
Financial Effect on Future Periods	0
Amount Considered Significant on Individual Project Gross Profit	1,000,000.0	1,000,000.0
Construction [Member]
Change in Accounting Estimate [Line Items]
Increase (Decrease) on Project Profitability	3,500,000
Amount Considered Significant on Individual Project Gross Profit	1,000,000	1,000,000
Contracts Accounted for under Percentage of Completion [Member] | Large Project Construction [Member]
Change in Accounting Estimate [Line Items]
Increase (Decrease) on Project Profitability	8,200,000	9,200,000
Amount Considered Significant on Individual Project Gross Profit	1,000,000
Contracts Accounted for under Percentage of Completion [Member] | Large Project Construction [Member] | Noncontrolling Interest [Member]
Change in Accounting Estimate [Line Items]
Increase (Decrease) on Project Profitability	700,000	1,700,000
Upward Estimate Change [Member] | Construction [Member]
Change in Accounting Estimate [Line Items]
Gross Profit	4,000,000	4,500,000
Upward Estimate Change [Member] | Construction [Member] | Minimum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	0	0
Upward Estimate Change [Member] | Construction [Member] | Maximum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	0	0
Upward Estimate Change [Member] | Large Project Construction [Member]
Change in Accounting Estimate [Line Items]
Number of Projects with Estimate Changes	5	3
Increase (Decrease) on Project Profitability	16,100,000	16,100,000
Upward Estimate Change [Member] | Large Project Construction [Member] | Minimum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	1,300,000	1,600,000
Upward Estimate Change [Member] | Large Project Construction [Member] | Maximum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	7,900,000	7,400,000
Downward Estimate Change [Member] | Construction [Member] | Minimum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	(1,300,000)	0
Downward Estimate Change [Member] | Construction [Member] | Maximum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	(2,100,000)	0
Downward Estimate Change [Member] | Large Project Construction [Member]
Change in Accounting Estimate [Line Items]
Number of Projects with Estimate Changes	2	2
Increase (Decrease) on Project Profitability	(7,900,000)	(6,900,000)
Downward Estimate Change [Member] | Large Project Construction [Member] | Minimum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	(3,400,000)	(2,400,000)
Downward Estimate Change [Member] | Large Project Construction [Member] | Maximum [Member]
Change in Accounting Estimate [Line Items]
Range Of Effect On Gross Profit	$ (4,500,000)	$ (4,500,000)