Receivables, Net (Details) (USD $)	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	$ 211,526,000	$ 254,718,000	$ 173,606,000
Allowance for Accounts, Notes, Loans and Financing Receivable, Current	2,819,000	2,880,000	3,165,000
Receivables, net	208,707,000	251,838,000	170,441,000
Notes, Loans and Financing Receivable, Net, Noncurrent	2,000,000	2,000,000	2,000,000
Construction Contracts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	171,730,000	200,025,000	146,618,000
Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	101,659,000	122,987,000	69,095,000
Retentions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	70,071,000	77,038,000	77,523,000
Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	46,430,000	43,378,000	34,945,000
Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	23,641,000	33,660,000	42,578,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	13,741,000	27,125,000	34,348,000
Non-escrow retention receivable - 0 to 90 days past due	6,267,000	3,277,000	4,007,000
Non-escrow retention receivable - over 90 days past due	3,633,000	3,258,000	4,223,000
Construction Material Sales [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	26,959,000	30,356,000	13,964,000
Other Business Products and Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	12,837,000	24,337,000	13,024,000
Federal [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	2,306,000	2,811,000	3,587,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	1,169,000	2,462,000	2,690,000
Non-escrow retention receivable - 0 to 90 days past due	1,078,000	326,000	666,000
Non-escrow retention receivable - over 90 days past due	59,000	23,000	231,000
State [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	4,342,000	5,453,000	7,994,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	2,490,000	2,751,000	6,177,000
Non-escrow retention receivable - 0 to 90 days past due	795,000	860,000	600,000
Non-escrow retention receivable - over 90 days past due	1,057,000	1,842,000	1,217,000
Local [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	10,827,000	14,708,000	21,476,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	4,915,000	12,313,000	16,698,000
Non-escrow retention receivable - 0 to 90 days past due	3,720,000	1,326,000	2,426,000
Non-escrow retention receivable - over 90 days past due	2,192,000	1,069,000	2,352,000
Private [Member] | Non Escrow [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable, Gross, Current	6,166,000	10,688,000	9,521,000
Financing Receivable, Recorded Investment, Aging [Abstract]
Non-escrow retention receivable - current	5,167,000	9,599,000	8,783,000
Non-escrow retention receivable - 0 to 90 days past due	674,000	765,000	315,000
Non-escrow retention receivable - over 90 days past due	$ 325,000	$ 324,000	$ 423,000