Note 11 - Construction Joint Ventures - Schedule of Unconsolidated Construction Joint Ventures Revenue and Costs (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Cost of revenue		$ 497,811	$ 512,620
Net loss		(9,821)	(65,323)
Collaborative Arrangement [Member]
Revenue		49,655	79,722
Cost of revenue		53,269	79,336
Granite’s interest in gross profit (loss)		(3,614)	386
Granite’s interest in net income (loss)		(3,627)	418
Collaborative Arrangement [Member] | Corporate Joint Venture [Member]
Revenue		161,139	232,042
Cost of revenue		157,921	248,070
Net loss		3,167	(16,003)
Collaborative Arrangement [Member] | Co-venturer [Member] | Other Partners Interest in Partnerships [Member]
Revenue	[1]	111,484	152,320
Cost of revenue	[1]	104,652	168,734
Net loss	[1]	$ 6,794	$ (16,421)

[1] This balance is primarily related to local bank debt for equipment purchases and debt associated with our real estate investments.