Construction Joint Ventures - Schedule of Unconsolidated Construction Joint Ventures Revenue and Costs (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Variable Interest Entity [Line Items]
Unconsolidated Construction Joint Venture Revenue		$ 436,093	$ 550,115	$ 1,125,530	$ 1,517,419
Unconsolidated Construction Joint Venture Cost of Revenue		485,190	520,205	1,289,464	1,462,127
Unconsolidated Construction Joint Venture Gross Loss		(4,020)	(6,937)	(17,947)	(15,165)
Other Partners Interest in Partnerships [Member]
Variable Interest Entity [Line Items]
Unconsolidated Construction Joint Venture Revenue	[1]	285,064	396,672	746,905	1,096,834
Unconsolidated Construction Joint Venture Cost of Revenue	[1]	330,141	359,825	892,892	1,026,377
Reporting Entitys Interest in Joint Venture [Member]
Variable Interest Entity [Line Items]
Unconsolidated Construction Joint Venture Revenue		151,029	153,443	378,625	420,585
Unconsolidated Construction Joint Venture Cost of Revenue		$ 155,049	$ 160,380	$ 396,572	$ 435,750

[1] Partners’ interest and adjustments represents 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