Quarterly Financial Data (Details) (USD $)	3 Months Ended																12 Months Ended			3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended				3 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Kenny	Dec. 31, 2013 Kenny	Dec. 31, 2012 State [Member]	Dec. 31, 2013 Enterprise Improvement Plan [Member]	Dec. 31, 2012 Enterprise Improvement Plan [Member]	Dec. 31, 2011 Enterprise Improvement Plan [Member]	Dec. 31, 2010 Enterprise Improvement Plan [Member]	Sep. 30, 2013 Scenario, Adjustment [Member]	Jun. 30, 2013 Scenario, Adjustment [Member]	Sep. 30, 2013 Scenario, Previously Reported [Member]	Jun. 30, 2013 Scenario, Previously Reported [Member]	Sep. 30, 2013 Over-accrual of Pre-bid Costs [Member]	Sep. 30, 2013 Revision in Equipment Related Costs [Member]	Jun. 30, 2013 Revision in Equipment Related Costs [Member]
Quarterly Financial Data [Abstract]
Revenue, Net	$ 598,099,000		$ 739,750,000	[1]	$ 550,348,000	[2]	$ 378,704,000		$ 504,781,000		$ 728,482,000		$ 539,615,000		$ 310,160,000		$ 2,266,901,000	$ 2,083,037,000	$ 2,009,531,000
Gross profit	49,751,000		55,858,000	[1]	49,596,000	[2]	30,058,000		56,808,000		101,099,000		51,916,000		24,936,000		185,263,000	234,759,000	247,963,000
Gross profit as a percent of revenue	8.30%		7.60%	[1]	9.00%	[2]	7.90%		11.30%		13.90%		9.60%		8.00%
Net (loss) income	33,255,000	[3]	(6,533,000)	[1],[3]	(1,782,000)	[2],[3]	19,826,000	[3]	(18,374,000)	[4]	(45,746,000)	[4]	(4,487,000)	[4]	8,687,000	[4]	44,766,000	(59,920,000)	(66,085,000)								(2,100,000)	1,400,000	(4,500,000)	(3,200,000)
Net income (loss) as a percent of revenue	(5.60%)		0.90%	[1]	0.30%	[2]	(5.20%)		3.60%		6.30%		0.80%		(2.80%)
Net income (loss) attributable to Granite	(28,898,000)		13,038,000	[1]	1,419,000	[2]	(21,982,000)		17,987,000		37,121,000		1,949,000		(11,773,000)		(36,423,000)	45,283,000	51,161,000
Net income (loss) attributable to Granite as a percent of revenue	(4.80%)		1.80%	[1]	0.30%	[2]	(5.80%)		3.60%		5.10%		0.40%		(3.80%)
Net (loss) income per share attributable to common shareholders:
Basic (in dollars per share)	$ (0.74)		$ 0.34	[1]	$ 0.04	[2]	$ (0.57)		$ 0.46		$ 0.96		$ 0.05		$ (0.31)		$ (0.94)	$ 1.17	$ 1.32
Diluted (in dollars per share)	$ (0.74)		$ 0.34	[1]	$ 0.04	[2]	$ (0.57)		$ 0.46		$ 0.94		$ 0.05		$ (0.31)		$ (0.94)	$ 1.15	$ 1.31
Restructuring and impairment charges (gains), net																							48,975,000	(3,728,000)	2,181,000	109,300,000
Asset Impairment Charges	3,200,000																3,164,000	0	0
(Loss) income before (benefit from) provision for income taxes																	64,029,000	(81,029,000)	(89,433,000)								(3,000,000)	1,900,000
Effect of adjustments in period																															1,400,000	1,600,000	1,700,000
Gain on sales of property and equipment									18,000,000
Tax benefit from release of state valuation allowance																	0	(5,803,000)	0			5,800,000
Acquisition-related costs																				$ 4,400,000	$ 4,400,000

[1] Net income for the quarter ended September 30 is approximately $2.1 million ($3.0 million pre-tax) higher than the amount previously reported in our Quarterly Report Form 10-Q for the quarterly period ended September 30, 2013 of $4.5 million. The pre-tax adjustments were primarily related to (i) an over-accrual of pre-bid costs which affected selling, general and administrative expenses and accrued and other current liabilities in the amount of $1.4 million and (ii) a revision in equipment-related costs, which affected cost of revenue and property and equipment in the amount of $1.6 million.

[2] Net income for the quarter ended June 30 is approximately $1.4 million ($1.9 million pre-tax) lower than the amounts previously reported in our Form 10-Q for the quarter period ended June 30, 2013 of $3.2 million. The pre-tax adjustments were primarily related to equipment-related costs of $1.7 million.

[3] Included in our net loss for the quarter ended December 31, 2013 were restructuring charges of $49.0 million related to the non-cash impairment of certain real estate development projects within the Real Estate segment and certain non-performing quarry sites within the Construction Materials segment. Also included in the 2013 fourth quarter was a $3.2 million non-cash impairment charge related to our process of continually optimizing our assets separate from the EIP.

[4] Included in our net income for the quarter ended December 31, 2012 was an $18.0 million gain from the sale of an underutilized quarry related to our process of continually optimizing our assets separate from the EIP. In addition, net income for the quarter ended December 31, 2012 included a $5.8 million tax benefit from the release of a state valuation allowance and $4.4 million of Kenny related acquisition costs.