Note 9 - Construction Joint Ventures - Schedule of Unconsolidated Construction Joint Ventures Revenue and Costs (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cost of revenue										$ 2,704,497	$ 2,824,226	$ 2,725,092
Net income		$ (20,433)	$ 32,423	$ 55,747	$ (65,323)	$ 5,687	$ (98,357)	$ (973)	$ (72,538)	2,414	(166,181)	(56,702)
Collaborative Arrangement [Member]
Revenue										294,064	359,236	421,360
Cost of revenue										295,045	410,675	542,672
Granite’s interest in gross loss										(981)	(51,439)	(121,312)
Granite’s interest in net loss										(768)	(51,486)	(120,611)
Collaborative Arrangement [Member] | Corporate Joint Venture [Member]
Revenue										820,586	918,716	1,471,157
Cost of revenue										835,899	1,193,358	1,900,524
Net income										(15,533)	(274,410)	(422,457)
Collaborative Arrangement [Member] | Co-venturer [Member] | Other Partners Interest in Partnerships [Member]
Revenue	[1]									526,522	559,480	1,049,797
Cost of revenue	[1]									540,854	782,683	1,357,852
Net income	[1]									$ (14,765)	$ (222,924)	$ (301,846)

[1] Partners’ interest and adjustments includes 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 and estimates primarily related to contract forecast and/or actual differences.