Investments in Affiliates - Investments in Affiliates (Details) (USD $)	3 Months Ended
	Mar. 31, 2015 project		Mar. 31, 2014		Dec. 31, 2014
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	$ 32,031,000		$ 33,336,000		$ 32,361,000
Equity Method Investments			15,900,000
Joint Venture Unconsolidated [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	32,031,000		33,336,000		32,361,000
Equity Method Investment, Summarized Financial Information, Assets	178,723,000		172,763,000		170,174,000
Equity Method Investments Summarized Financial Information Net Assets	101,212,000		95,561,000		97,639,000
Equity Method Investments	16,800,000				16,500,000
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Investments in and Advances to Affiliates [Line Items]
Unconsolidated Construction Joint Venture Revenue	443,407,000		349,167,000
Number of projects	11
Unconsolidated Construction Joint Venture Cost of Revenue	410,071,000		297,461,000
Joint Venture Unconsolidated [Member] | Other Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	9,392,000		10,983,000		9,738,000
Equity Method Investments	32,031,000		33,336,000		32,361,000
Joint Venture Unconsolidated [Member] | Equity Method investments in Real Estate Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	22,639,000		22,353,000		22,623,000
Joint Venture Unconsolidated [Member] | Minimum [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	23,900,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Investments in and Advances to Affiliates [Line Items]
Unconsolidated Construction Joint Venture Revenue	308,120,000	[1]	259,857,000	[1]
Unconsolidated Construction Joint Venture Cost of Revenue	286,047,000	[1]	210,906,000	[1]
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Investments in and Advances to Affiliates [Line Items]
Unconsolidated Construction Joint Venture Revenue	135,287,000		89,310,000
Unconsolidated Construction Joint Venture Cost of Revenue	124,024,000		86,555,000
Unconsolidated Construction Joint Venture Gross Profit Loss	11,263,000		2,755,000
Real Estate Segment [Member] | Joint Venture Unconsolidated [Member] | Minimum [Member] | Real Estate Entities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Investments in and Advances to Affiliates [Line Items]
Real Estate Development Projects Range of Total Assets	1,900,000
Real Estate Segment [Member] | Joint Venture Unconsolidated [Member] | Maximum [Member] | Real Estate Entities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Investments in and Advances to Affiliates [Line Items]
Real Estate Development Projects Range of Total Assets	$ 61,800,000

[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.