Receivables, Net (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	$ 254,718,000				$ 247,283,000				$ 254,718,000	$ 247,283,000
Allowance for Accounts, Notes, Loans and Financing Receivable, Current	2,880,000				3,297,000				2,880,000	3,297,000
Receivables, net	251,838,000				243,986,000				251,838,000	243,986,000
Accounts Notes Loans and Financing Receivable Gross Current, Due In One Year From Balance Sheet	51,700,000								51,700,000
Accounts Notes Loans and Financing Receivable Gross Current, Due In Two Years From Balance Sheet	12,300,000								12,300,000
Accounts Notes Loans and Financing Receivable Gross Current, Due In Three Years From Balance Sheet	13,000,000								13,000,000
Segment Reporting Information, Revenue for Reportable Segment									2,204,566,000	1,960,262,000	2,146,974,000
Revenue, Net	539,548,000	728,578,000	484,674,000	256,731,000	417,228,000	670,850,000	454,204,000	220,683,000	2,009,531,000	1,762,965,000	1,963,479,000
Number of Customers With Receivable Balance in Excess of 10% of Total Receivables	0				0				0	0
Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes, Loans and Financing Receivable, Net, Noncurrent	2,000,000				1,800,000				2,000,000	1,800,000
Construction Contracts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	200,025,000				217,997,000				200,025,000	217,997,000
Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	122,987,000				121,664,000				122,987,000	121,664,000
Retentions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	77,038,000				96,333,000				77,038,000	96,333,000
Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	43,378,000				43,841,000				43,378,000	43,841,000
Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	33,660,000				52,492,000				33,660,000	52,492,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	27,125,000				38,914,000				27,125,000	38,914,000
Non-escrow retention receivable - 0 to 90 days past due	3,277,000				3,777,000				3,277,000	3,777,000
Non-escrow retention receivable - over 90 days past due	3,258,000				9,801,000				3,258,000	9,801,000
Construction Material Sales [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	30,356,000				17,674,000				30,356,000	17,674,000
Other Business Products and Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	24,337,000				11,612,000				24,337,000	11,612,000
Government [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage Of Revenue Attributable to Counterparty by Industry									83.80%	83.30%	85.60%
Government [Member] | Construction And Large Project Contruction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Segment Reporting Information, Revenue for Reportable Segment									1,700,000,000	1,500,000,000	1,700,000,000
Federal [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	2,811,000				3,080,000				2,811,000	3,080,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	2,462,000				2,587,000				2,462,000	2,587,000
Non-escrow retention receivable - 0 to 90 days past due	326,000				174,000				326,000	174,000
Non-escrow retention receivable - over 90 days past due	23,000				319,000				23,000	319,000
State [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	5,453,000				9,507,000				5,453,000	9,507,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	2,751,000				4,443,000				2,751,000	4,443,000
Non-escrow retention receivable - 0 to 90 days past due	860,000				628,000				860,000	628,000
Non-escrow retention receivable - over 90 days past due	1,842,000				4,436,000				1,842,000	4,436,000
California Department of Transportation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenue, Net									264,900,000	175,000,000	234,000,000
Percentage Of Revenue Attributable to Counterparty by Industry									13.20%	9.90%	11.90%
Maryland State Highway Administration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revenue, Net									52,500,000	181,000,000	119,800,000
Percentage Of Revenue Attributable to Counterparty by Industry									2.60%	10.30%	6.10%
Local [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	14,708,000				29,451,000				14,708,000	29,451,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	12,313,000				22,641,000				12,313,000	22,641,000
Non-escrow retention receivable - 0 to 90 days past due	1,326,000				2,800,000				1,326,000	2,800,000
Non-escrow retention receivable - over 90 days past due	1,069,000				4,010,000				1,069,000	4,010,000
Private [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	10,688,000				10,454,000				10,688,000	10,454,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	9,599,000				9,243,000				9,599,000	9,243,000
Non-escrow retention receivable - 0 to 90 days past due	765,000				175,000				765,000	175,000
Non-escrow retention receivable - over 90 days past due	$ 324,000				$ 1,036,000				$ 324,000	$ 1,036,000