Construction and Line Item Joint Ventures - Consolidated Construction Joint Ventures (Details) (USD $)	Sep. 30, 2011		Dec. 31, 2010		Sep. 30, 2010		Dec. 31, 2009
Construction Joint Venture [Line Items]
Cash and cash equivalents	$ 193,099,000		$ 252,022,000		$ 257,854,000		$ 338,956,000
Other current assets	29,526,000		42,555,000		42,409,000
Total current assets	990,994,000		913,856,000		1,099,980,000
Total assets	1,618,469,000		1,535,533,000		1,751,971,000
Accounts payable	216,600,000		129,700,000		206,993,000
Billings in excess of costs and estimated earnings	89,505,000		120,185,000		157,233,000
Accrued expenses and other current liabilities	185,624,000		150,773,000		173,547,000
Total current liabilities	516,770,000		438,777,000		585,374,000
Minimum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	227,600,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	45.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	57,600,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	20.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	52,900,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	21,100,000
Minimum [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	2,400,000
Maximum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	312,100,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	60.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	975,400,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	49.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	154,900,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	71,300,000
Maximum [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	196,100,000
Partnership Interest [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,700,000,000
Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Cash and cash equivalents	65,350,000	[1]	109,380,000	[1]	103,367,000	[1]
Other current assets	31,215,000	[2]	50,344,000	[2]	44,351,000	[2]
Total current assets	96,565,000		159,724,000		147,718,000
Noncurrent assets	9,821,000		2,561,000		894,000
Total assets	106,386,000	[3]	162,285,000	[3]	148,612,000	[3]
Accounts payable	36,660,000		33,078,000		33,934,000
Billings in excess of costs and estimated earnings	17,116,000	[1]	46,475,000	[1]	63,783,000	[1]
Accrued expenses and other current liabilities	5,997,000		11,633,000		11,195,000
Total current liabilities	59,773,000		91,186,000		108,912,000
Noncurrent liabilities	33,000		3,000		5,000
Total liabilities	59,806,000	[3]	91,189,000	[3]	108,917,000	[3]
Number of Active Joint Venture Projects	2
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	9
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	600,000,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	$ 1,100,000,000
Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	4

[1] The volume and stage of completion of contracts from our consolidated construction joint ventures may cause fluctuations in cash and cash equivalents as well as billings in excess of costs and estimated earnings between periods.

[2] 2Prior period amounts have been revised to conform to current year presentation. The revisions had no impact on the consolidated balances or on the accounting for consolidated construction joint ventures.

[3] The assets and liabilities of each joint venture relate solely to that joint venture. The decision to distribute joint venture cash and cash equivalents and assets must generally be made jointly by all of the partners and, accordingly, these cash and cash equivalents and assets generally are not available for the working capital needs of Granite.