Construction and Line Item Joint Ventures - Unconsolidated Construction Joint Ventures (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 project		Dec. 31, 2011		Dec. 31, 2010
Construction Joint Venture [Line Items]
Deficit in unconsolidatedconstruction joint venture	$ 200,000
Equity in Construction Joint Ventures Current Assets Excluding Deficit in Equity	105,572,000		101,029,000
Partnership Interest [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	1,600,000,000
Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of active construction joint venture projects	4
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of active construction joint venture projects	10
Cash and cash equivalents	244,686,000	[1]	338,681,000	[1]
Other assets	301,412,000		264,901,000
Accounts payable	114,039,000		85,075,000
Billings in excess of costs and estimated earnings	161,268,000	[1]	280,650,000	[1]
Other liabilities	6,106,000		8,595,000
Revenue	1,042,209,000		938,867,000		604,209,000
Cost of revenue	785,079,000		765,446,000		550,170,000
Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of active construction joint venture projects	5
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	553,800,000
Interest in assets	203,553,000		238,603,000
Interest in liabilities	97,981,000		137,574,000
Revenue	376,427,000		315,777,000		189,304,000
Cost of revenue	273,239,000		246,106,000		177,396,000
Granite's interest in gross profit	103,188,000		69,671,000		11,908,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	1,100,000,000
Interest in assets	342,545,000		364,979,000
Interest in liabilities	183,432,000		236,746,000
Revenue	665,782,000	[2]	623,090,000		414,905,000
Cost of revenue	511,840,000	[2]	519,340,000		372,774,000
Minimum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	5,800,000
Minimum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	59,400,000
Minimum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	42,000,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Proportionate Share of the Consolidated and Unconsolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	45.00%
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Proportionate Share of the Consolidated and Unconsolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	20.00%
Revenue Per Project Remaining to be Recognized on Unconsolidated and Line Item Construction Joint Ventures	300,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	21,900,000
Revenue Per Project Remaining to be Recognized on Unconsolidated and Line Item Construction Joint Ventures	1,400,000
Maximum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	334,700,000
Maximum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	1,200,000,000
Maximum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	133,400,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Proportionate Share of the Consolidated and Unconsolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	65.00%
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Proportionate Share of the Consolidated and Unconsolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%
Revenue Per Project Remaining to be Recognized on Unconsolidated and Line Item Construction Joint Ventures	156,000,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	58,000,000
Revenue Per Project Remaining to be Recognized on Unconsolidated and Line Item Construction Joint Ventures	$ 27,600,000

[1] 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. 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.

[2] Partners’ 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.