Construction Joint Ventures (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Construction Joint Venture
Contracts Revenue	$ 429,269	$ 331,346	$ 656,118	$ 540,833
Net cash provided by operating activities			22,686	(53,113)
Unconsolidated Construction Joint Venture
Construction Joint Venture
Performance Guarantees	88,900	76,800	88,900	76,800	$ 83,100
Granite Construction [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Unconsolidated Construction Joint Venture Net (Loss) Income	(9,700)	(2,900)	(8,200)	5,600
Partnership Interest [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	$ 5,500,000		$ 5,500,000
Joint Venture Consolidated | Consolidated Construction Joint Venture
Construction Joint Venture
Number of Active Joint Venture Projects	4		4
Contracts Revenue	$ 49,500	33,000	$ 85,000	55,100
Net cash provided by operating activities			19,200	12,800
Joint Venture Consolidated | Minimum | Consolidated Construction Joint Venture
Construction Joint Venture
Construction Contract Value	49,100		49,100
Revenue Remaining to be Recognized on Consolidated Construction Joint Ventures	$ 11,600		$ 11,600
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%		50.00%
Joint Venture Consolidated | Maximum | Consolidated Construction Joint Venture
Construction Joint Venture
Construction Contract Value	$ 267,400		$ 267,400
Revenue Remaining to be Recognized on Consolidated Construction Joint Ventures	$ 147,300		$ 147,300
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	65.00%		65.00%
Joint Venture Unconsolidated | Unconsolidated Construction Joint Venture
Construction Joint Venture
Unconsolidated Construction Joint Venture Net (Loss) Income	$ 17,600	(4,400)	$ 26,200	29,300
Number of Active Joint Venture Projects	11		11
Number of Active Joint Venture Projects Greater than $1Billion	3		3
Joint Venture Unconsolidated | Line Item Joint Venture
Construction Joint Venture
Number of Active Joint Venture Projects	2		2
Contracts Revenue	$ 6,800	$ 9,600	$ 14,700	$ 14,000
Joint Venture Unconsolidated | Minimum | Unconsolidated Construction Joint Venture
Construction Joint Venture
Construction Contract Value	$ 79,400		$ 79,400
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	20.00%		20.00%
Joint Venture Unconsolidated | Minimum | Line Item Joint Venture
Construction Joint Venture
Construction Contract Value	$ 66,200		$ 66,200
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	800		800
Joint Venture Unconsolidated | Maximum | Unconsolidated Construction Joint Venture
Construction Joint Venture
Construction Contract Value	$ 3,700,000		$ 3,700,000
Proportionate Share of the Joint Ventures Equity Owned by or Beneficial Interest in the Reporting Entity Directly or Indirectly	50.00%		50.00%
Joint Venture Unconsolidated | Maximum | Line Item Joint Venture
Construction Joint Venture
Construction Contract Value	$ 74,700		$ 74,700
Revenue Per Project Remaining to be Recognized on Line Item Construction Joint Ventures	7,300		7,300
Reporting Entitys Interest in Joint Venture [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,800,000		1,800,000
Reporting Entitys Interest in Joint Venture [Member] | Minimum | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	1,300		1,300
Reporting Entitys Interest in Joint Venture [Member] | Minimum | Line Item Joint Venture
Construction Joint Venture
Construction Contract Value	30,700		30,700
Reporting Entitys Interest in Joint Venture [Member] | Maximum | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	436,600		436,600
Reporting Entitys Interest in Joint Venture [Member] | Maximum | Line Item Joint Venture
Construction Joint Venture
Construction Contract Value	44,700		44,700
Other Partners Interest in Partnerships [Member] | Unconsolidated Construction Joint Venture
Construction Joint Venture
Revenue Remaining to be Recognized on Unconsolidated Construction Joint Ventures	$ 3,700,000		$ 3,700,000