Construction and Line Item Joint Ventures - Unconsolidated Construction Joint Ventures (Details) (USD $)	3 Months Ended						6 Months Ended		9 Months Ended
	Sep. 30, 2012		Jun. 30, 2012		Sep. 30, 2011		Jun. 30, 2012		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011
Construction Joint Venture [Line Items]
Equity in construction joint ventures	$ 97,890,000				$ 97,415,000				$ 97,890,000		$ 97,415,000		$ 101,029,000
Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	5								5
Partnership Interest [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,600,000,000								1,600,000,000
Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	2								2
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	8								8
Unconsolidated Construction Joint Venture Revenue	286,308,000	[1]	284,095,000	[1]	243,654,000	[1]	489,926,000	[1]	776,235,000	[1]	667,920,000	[1]
Unconsolidated Construction Joint Venture Cost of Revenue	200,688,000	[1]	227,389,000	[1]	212,485,000	[1]	397,001,000	[1]	597,689,000	[1]	546,495,000	[1]
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	224,748,000				243,425,000				224,748,000		243,425,000		238,603,000
Unconsolidated Construction Joint Venture Liabilities	126,858,000				146,010,000				126,858,000		146,010,000		137,574,000
Unconsolidated Construction Joint Venture Revenue	104,629,000				85,575,000				278,492,000		219,563,000
Unconsolidated Construction Joint Venture Cost of Revenue	70,848,000				71,979,000				208,518,000		175,630,000
Unconsolidated Construction Joint Venture Gross Profit Loss	33,781,000				13,596,000				69,974,000		43,933,000
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	600,000,000								600,000,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	353,165,000				378,523,000				353,165,000		378,523,000		364,979,000
Unconsolidated Construction Joint Venture Liabilities	219,807,000				251,091,000				219,807,000		251,091,000		236,746,000
Unconsolidated Construction Joint Venture Revenue	181,679,000	[1],[2]	183,861,000	[1],[2]	158,079,000	[1],[2]	316,064,000	[1],[2]	497,743,000	[1],[2]	448,357,000	[1],[2]
Unconsolidated Construction Joint Venture Cost of Revenue	129,840,000	[1],[2]	150,091,000	[1],[2]	140,506,000	[1],[2]	259,331,000	[1],[2]	389,171,000	[1],[2]	370,865,000	[1],[2]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,000,000,000								1,000,000,000
Minimum [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	2,500,000								2,500,000
Minimum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	245,100,000								245,100,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	45.00%								45.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	59,400,000								59,400,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	20.00%								20.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	42,000,000								42,000,000
Minimum [Member] | 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	400,000								400,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	21,900,000								21,900,000
Maximum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	334,300,000								334,300,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	60.00%								60.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	1,200,000,000								1,200,000,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%								50.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	133,200,000								133,200,000
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	29,000,000								29,000,000
Maximum [Member] | 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	186,600,000								186,600,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	55,700,000								55,700,000
Cash and Cash Equivalents [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	304,065,000	[3]			356,399,000	[3]			304,065,000	[3]	356,399,000	[3]	338,681,000	[3]
Other Assets, Current and Longterm [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	273,848,000				265,549,000				273,848,000		265,549,000		264,901,000
Accounts Payable [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	94,788,000				85,602,000				94,788,000		85,602,000		85,075,000
Billings in Excess of Costs and Estimated Earnings [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	243,578,000	[3]			302,039,000	[3]			243,578,000	[3]	302,039,000	[3]	280,650,000	[3]
Accrued Liabilities [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	8,299,000				9,460,000				8,299,000		9,460,000		8,595,000
Scenario, Previously Reported [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Revenue			663,536,000	[1]			869,368,000	[1]
Unconsolidated Construction Joint Venture Cost of Revenue			544,838,000	[1]			714,450,000	[1]
Scenario, Previously Reported [Member] | Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Revenue			563,302,000	[1],[2]			695,505,000	[1],[2]
Unconsolidated Construction Joint Venture Cost of Revenue			$ 467,540,000	[1],[2]			$ 576,780,000	[1],[2]

[1] 1While Granite’s interest in revenue, cost of revenue and gross profit were correctly stated, total and partners’ interest for revenue and cost of revenue for the three and six month periods ended June 30, 2012 were inadvertently misstated in our Quarterly Report for the quarter ended June 30, 2012. Total revenue, partner’s interest in revenue, total cost of revenue and partners’ interest in cost of revenue reported was (in thousands): $663,536, $563,302, $544,838 and $467,540, respectively, for the three months ended June 30, 2012, and $869,368, $695,505, $714,450 and $576,780, respectively, for the six months ended June 30, 2012. Total revenue, partner’s interest in revenue, total cost of revenue and partners’ interest in cost of revenue should have been (in thousands): $284,095, $183,861, $227,389, and $150,091, respectively, for the three months ended June 30, 2012, and $489,926, $316,064, $397,001, and $259,331, respectively, for the six months ended June 30, 2012.

[2] 2Partners’ interest represents amounts to reconcile total revenue and total cost of revenue as reported by our partners to Granite’s interest, adjusted to reflect our accounting policies.

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