Significant Accounting Policies (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011	Dec. 31, 2011
Costs and estimated earnings in excess of billings related to the entity's contracts and joint venture contracts [Abstract]
Unbilled costs and profits incurred to date	$ 141,980,000	[1]		$ 141,980,000	[1]		$ 107,645,000	[1]
Unapproved change orders	107,786,000			107,786,000			136,704,000
Claims	161,896,000			161,896,000			114,049,000
Total	411,662,000			411,662,000			358,398,000
Unapproved change orders and claims subject to pending litigation	72,200,000			72,200,000			85,200,000
Change in Accounting Estimate [Line Items]
Income from Construction Operations	54,676,000		62,036,000	(282,535,000)		117,584,000
Net Income (Loss)	42,591,000		35,477,000	(307,035,000)		62,100,000
Diluted Earnings (Loss) per Common Share (in dollars per share)	$ 0.88		$ 0.74	$ (6.47)		$ 1.30
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Income from Construction Operations	12,400,000			12,400,000
Net Income (Loss)	$ 7,200,000			$ 7,200,000
Diluted Earnings (Loss) per Common Share (in dollars per share)	$ 0.15			$ 0.15

[1] Represents the excess of contract costs and profits recognized to date on the percentage of completion accounting method over the amount of contract billings to date on certain contracts.