Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Revenue, Net	$ 630,162	$ 751,376	$ 569,242	$ 420,249	$ 589,789	$ 719,764	$ 585,870	$ 379,847	$ 2,371,029	$ 2,275,270	$ 2,266,901
Gross profit	$ 102,008	$ 96,253	$ 65,045	$ 40,052	$ 73,726	$ 66,292	$ 80,729	$ 21,499	303,358	242,247	177,177
Gross profit as a percent of revenue	16.20%	12.80%	11.40%	9.50%	12.50%	9.30%	14.10%	5.60%
Net (loss) income	$ 35,139	$ 32,180	$ 9,539	$ (8,610)	$ 20,825	$ 14,105	$ 22,207	$ (21,261)	68,248	35,876	(44,766)
Net income (loss) as a percent of revenue	5.60%	4.30%	1.70%	(2.00%)	3.50%	2.00%	3.80%	(5.60%)
Net income (loss) attributable to Granite	$ 28,673	$ 30,759	$ 9,613	$ (8,560)	$ 16,976	$ 15,282	$ 13,641	$ (20,553)	$ 60,485	$ 25,346	$ (36,423)
Net income (loss) attributable to Granite as a percent of revenue	4.60%	4.10%	1.70%	(2.00%)	2.90%	2.10%	2.30%	(5.40%)
Net (loss) income per share attributable to common shareholders:
Basic (in dollars per share)	$ 0.73	$ 0.78	$ 0.24	$ (0.22)	$ 0.43	$ 0.39	$ 0.35	$ (0.53)	$ 1.54	$ 0.65	$ (0.94)
Diluted (in dollars per share)	$ 0.72	$ 0.77	$ 0.24	$ (0.22)	$ 0.43	$ 0.38	$ 0.34	$ (0.53)	$ 1.52	$ 0.64	$ (0.94)
Other impairment (gains) charges										$ (1,360)	$ 3,164
(Loss) income before (benefit from) provision for income taxes									$ (103,427)	(55,597)	64,029
Asset impairment gains	$ 1,300									(1,300)
Noncontrolling Interest [Member]
Quarterly Financial Data [Abstract]
Net (loss) income									7,763	10,530	(8,343)
Enterprise Improvement Plan [Member]
Net (loss) income per share attributable to common shareholders:
Restructuring and impairment (gains) charges, net									(6,003)	(1,283)	48,975
Contract Termination [Member] | Enterprise Improvement Plan [Member]
Net (loss) income per share attributable to common shareholders:
Restructuring and impairment (gains) charges, net	1,000				$ (1,300)					(1,283)	3,234
Restructuring Type, Real Estate Asset Impairment [Member]
Net (loss) income per share attributable to common shareholders:
Other impairment (gains) charges									0
Restructuring Type, Real Estate Asset Impairment [Member] | Enterprise Improvement Plan [Member]
Net (loss) income per share attributable to common shareholders:
Restructuring and impairment (gains) charges, net									(4,959)	$ 0	31,090
Other impairment (gains) charges											31,100
Restructuring Type, Real Estate Asset Impairment [Member] | Enterprise Improvement Plan [Member] | Noncontrolling Interest [Member]
Net (loss) income per share attributable to common shareholders:
Restructuring and impairment (gains) charges, net									$ 3,300		$ 3,900
Reclassification Adjustment [Member]
Quarterly Financial Data [Abstract]
Gross profit		$ 4,600	$ 800	$ 100
Reclassificaiton adjustment [Member]
Quarterly Financial Data [Abstract]
Gross profit	6,100					$ 400	$ 1,700	$ (100)
Previously reported [Member]
Quarterly Financial Data [Abstract]
Gross profit	$ 79,800	$ 100,900	$ 65,800	$ 40,100		$ 66,700	$ 82,400	$ 21,400