Construction and Line Item Joint Ventures - Consolidated Construction Joint Ventures (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Construction Joint Venture [Line Items]
Cash and cash equivalents	$ 255,961,000		$ 229,121,000		$ 321,990,000	$ 256,990,000
Other current assets	23,033,000		30,711,000
Total current assets	970,178,000		950,203,000
Property and equipment, net	409,653,000		436,859,000
Total assets	1,620,494,000		1,617,155,000		1,729,487,000
Accounts payable	151,935,000		160,706,000
Billings in excess of costs and estimated earnings	108,992,000		138,375,000
Accrued expenses and other current liabilities	200,652,000		197,242,000
Contracts Revenue	1,186,445,000		1,251,197,000		984,106,000
Net Cash Provided by (Used in) Operating Activities	43,142,000		5,380,000		91,790,000
Partnership Interest [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	5,700,000,000
Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Cash and cash equivalents	61,276,000	[1]	38,800,000	[1]
Receivables, net	36,781,000		38,372,000
Costs in Excess of Billings	1,746,000		4,778,000
Total current assets	99,803,000		81,950,000
Property and equipment, net	11,969,000		22,216,000
Total assets	111,772,000	[2]	104,166,000	[2]
Accounts payable	18,009,000		16,937,000
Billings in excess of costs and estimated earnings	32,830,000	[1]	60,185,000	[1]
Accrued expenses and other current liabilities	2,714,000		11,299,000
Total liabilities	53,553,000	[2]	88,421,000	[2]
Number of active construction joint venture projects	3
Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of active construction joint venture projects	10
Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Number of active construction joint venture projects	3
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	1,700,000,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	4,000,000,000
Minimum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	32,700,000
Deferred Revenue	200,000
Contracts Revenue	155,100,000		170,000,000		222,300,000
Net Cash Provided by (Used in) Operating Activities	22,500,000		10,900,000		25,200,000
Minimum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	72,800,000
Minimum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	42,700,000
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	55.00%
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%
Minimum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	28,900,000
Maximum [Member] | Joint Venture Consolidated [Member] | Consolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	364,400,000
Deferred Revenue	70,200,000
Maximum [Member] | Joint Venture Unconsolidated [Member] | Unconsolidated Construction Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	3,100,000,000
Maximum [Member] | Joint Venture Unconsolidated [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	86,000,000
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%
Maximum [Member] | Reporting Entitys Interest in Joint Venture [Member] | Line Item Joint Venture [Member]
Construction Joint Venture [Line Items]
Total Construction Contract Value	$ 63,600,000

[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 costs in excess of billings and estimated earnings between periods.

[2] 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 until distributed.