Construction Joint Ventures - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) project	Mar. 31, 2017 USD ($)
Construction Joint Venture
Number of active construction joint venture projects | project	1
Construction Contract Value	$ 66,200
Construction	269,243	$ 226,849
Line Item Joint Venture
Construction Joint Venture
Construction	800	8,000
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,400,000
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	$ 2,800,000
Joint Venture Consolidated
Construction Joint Venture
Number of active construction joint venture projects | project	6
Construction Contract Value	$ 1,200,000
Joint Venture Consolidated | Minimum [Member]
Construction Joint Venture
Construction Contract Value	49,900
Joint Venture Consolidated | Maximum [Member]
Construction Joint Venture
Construction Contract Value	409,700
Joint Venture Consolidated | Consolidated Construction Joint Venture
Construction Joint Venture
Construction	43,800	35,500
Net cash provided by operating activities	$ 2,500	6,500
Joint Venture Consolidated | Consolidated Construction Joint Venture | Minimum [Member]
Construction Joint Venture
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%
Joint Venture Consolidated | Consolidated Construction Joint Venture | Maximum [Member]
Construction Joint Venture
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	65.00%
Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture
Construction Joint Venture
Number of active construction joint venture projects | project	10
Construction Contract Value	$ 12,100,000
Unconsolidated Construction Joint Venture Net (Loss) Income	141,000	8,600
Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture | Minimum [Member]
Construction Joint Venture
Construction Contract Value	$ 77,300
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	20.00%
Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture | Maximum [Member]
Construction Joint Venture
Construction Contract Value	$ 3,700
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%
Partnership Interest | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	$ 4,200,000
Granite Construction [Member]
Construction Joint Venture
Construction Contract Value	49,000
Revenue Remaining to be Recognized on Consolidated Construction Joint Ventures	500
Granite Construction [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Unconsolidated Construction Joint Venture Net (Loss) Income	2,600	$ 1,500
Granite Construction [Member] | Joint Venture Consolidated
Construction Joint Venture
Construction	469,500
Granite Construction [Member] | Joint Venture Consolidated | Minimum [Member]
Construction Joint Venture
Construction	2,800
Granite Construction [Member] | Joint Venture Consolidated | Maximum [Member]
Construction Joint Venture
Construction	196,100
Granite Construction [Member] | Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture
Construction Joint Venture
Construction	1,400
Granite Construction [Member] | Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture | Minimum [Member]
Construction Joint Venture
Construction	2,300
Granite Construction [Member] | Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture | Maximum [Member]
Construction Joint Venture
Construction	$ 326,500