Note 11 - Construction Joint Ventures - Schedule of Unconsolidated Construction Joint Ventures Revenue and Costs (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended	9 Months Ended
		Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Cost of revenue		$ 996,678		$ 911,100		$ 2,417,945	$ 2,144,946
Granite’s interest in gross loss2			$ 134,200		$ 133,200
Collaborative Arrangement [Member]
Revenue		97,978		151,029		267,315	378,625
Cost of revenue		138,443		155,049		440,951	396,572
Granite’s interest in gross loss2	[1]	(40,465)		(4,020)		(173,636)	(17,947)
Collaborative Arrangement [Member] | Corporate Joint Venture [Member]
Revenue		421,977		436,093		1,273,982	1,125,530
Cost of revenue		441,898		485,190		1,309,867	1,289,464
Collaborative Arrangement [Member] | Co-venturer [Member] | Other Partners Interest in Partnerships [Member]
Revenue	[1]	323,999		285,064		1,006,667	746,905
Cost of revenue	[2]	$ 303,455		$ 330,141		$ 868,916	$ 892,892

[1] While total revenue, Granite's interest in revenue, total cost of revenue, and total net loss were correctly stated, Granite's interest in cost of revenue, gross loss and net loss for the three and six months ended June 30, 2019 were misstated for the quarter ended June 30, 2019. Granite's originally reported interest in cost of revenue, gross loss and net loss was: $144.0 million, $107.2 million and $106.3 million, respectively, for the three months ended June 30, 2019 and was $275.5 million, $106.2 million and $105.8 million, respectively, for the six months ended June 30, 2019. Granite's interest in cost of revenue, gross loss and net loss should have been: $171.0 million, $134.2 million and $133.3 million, respectively, for the three months ended June 30, 2019 and $302.5 million, $133.2 million and $132.8 million, respectively, for the six months ended June 30, 2019. The misstatements did not impact the condensed consolidated balance sheet, statements of operations, statements of comprehensive loss or statements of shareholders' equity in any period. However, the misstatements did result in a misclassification of $27.0 million within operating activities of the condensed consolidated statement of cash flows for the six months ended June 30, 2019 to equity in net loss from unconsolidated joint ventures from accrued expenses and other current liabilities, net. There was no impact to the net cash used in operating activities for the six months ended June 30, 2019. We assessed the materiality of the errors in accordance with the SEC's Staff Accounting Bulletin 99 and concluded that the errors were not material to either of these previously issued financial statements. Accordingly, we will revise our previously issued financial statements prospectively to correct these errors.

[2] 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 differences.