Construction and Line Item Joint Ventures - Unconsolidated Construction Joint Ventures (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Construction Joint Venture [Line Items]
Equity in construction joint ventures	$ 181,259,000		$ 161,063,000		$ 181,259,000		$ 161,063,000		$ 162,673,000
Granite Construction [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Revenue	1,800,000		21,300,000		28,100,000		53,200,000
Partnership Interest [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	6,100,000,000				6,100,000,000
Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	3				3
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	11				11
Unconsolidated Construction Joint Venture Revenue	313,945,000		363,523,000		1,055,276,000		848,082,000
Unconsolidated Construction Joint Venture Cost of Revenue	338,848,000		290,112,000		982,014,000		661,587,000
Unconsolidated Construction Joint Venture Revenue	(25,200,000)		71,100,000		75,200,000		182,800,000
Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of Active Joint Venture Projects	4				4
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	1,800,000,000				1,800,000,000
Unconsolidated Construction Joint Venture Assets	293,467,000		294,304,000		293,467,000		294,304,000		296,391,000
Unconsolidated Construction Joint Venture Liabilities	112,208,000		133,241,000		112,208,000		133,241,000		133,718,000
Unconsolidated Construction Joint Venture Revenue	100,877,000		103,868,000		313,825,000		262,066,000
Unconsolidated Construction Joint Venture Cost of Revenue	99,187,000		86,308,000		285,381,000		208,803,000
Unconsolidated Construction Joint Venture Gross Profit Loss	1,690,000		17,560,000		28,444,000		53,263,000
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	4,300,000,000				4,300,000,000
Unconsolidated Construction Joint Venture Assets	530,585,000		557,857,000		530,585,000		557,857,000		612,530,000
Unconsolidated Construction Joint Venture Liabilities	269,264,000		336,885,000		269,264,000		336,885,000		371,760,000
Unconsolidated Construction Joint Venture Revenue	213,068,000	[1]	259,655,000	[1]	741,451,000	[1]	586,016,000	[1]
Unconsolidated Construction Joint Venture Cost of Revenue	239,661,000	[1]	203,804,000	[1]	696,633,000	[1]	452,784,000	[1]
Minimum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	32,400,000				32,400,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	55.00%				55.00%
Minimum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	72,800,000				72,800,000
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	42,600,000				42,600,000
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	100,000				100,000
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	300,000				300,000
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	28,700,000				28,700,000
Maximum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	364,300,000				364,300,000
Proportionate Share of the Consolidated Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	65.00%				65.00%
Maximum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	3,100,000,000				3,100,000,000
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	86,100,000				86,100,000
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	27,600,000				27,600,000
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	696,900,000				696,900,000
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Construction Contract Value	63,800,000				63,800,000
Cash and Cash Equivalents [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Assets	286,040,000	[2]	412,506,000	[2]	286,040,000	[2]	412,506,000	[2]	385,094,000	[2]
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	538,012,000		439,655,000		538,012,000		439,655,000		523,827,000
Accounts Payable [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	141,630,000		127,695,000		141,630,000		127,695,000		155,985,000
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	178,781,000	[2]	274,052,000	[2]	178,781,000	[2]	274,052,000	[2]	245,341,000	[2]
Accrued Liabilities [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Unconsolidated Construction Joint Venture Liabilities	$ 61,061,000		$ 68,379,000		$ 61,061,000		$ 68,379,000		$ 104,152,000

[1] 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.

[2] 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 until distributed.