Equity (Details) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017		Jun. 30, 2016
Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance				$ 922,591		$ 870,121
Purchase of common stock				(6,568)	[1]	(4,845)	[2]
Other transactions with shareholders	[3]			11,987		8,623
Transactions with noncontrolling interests, net						3,355
Net income (loss)		$ 14,133	$ 14,199	(9,657)		3,758
Net Income (Loss) Attributable to Noncontrolling Interest		2,139	4,327	2,078		5,005
Net loss		16,272	18,526	(7,579)		8,763
Dividends on common stock				(10,354)		(10,292)
Stockholders' equity, ending balance		910,077	869,015	$ 910,077		$ 869,015
Shares Purchased for Tax Withholding for Share Based Compensation				133,000		109,000
Granite Construction [Member]
Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance				$ 885,988		$ 839,237
Purchase of common stock				(6,568)	[1]	(4,845)	[2]
Other transactions with shareholders	[3]			11,987		8,623
Transactions with noncontrolling interests, net						0
Net income (loss)				(9,657)		3,758
Dividends on common stock				(10,354)		(10,292)
Stockholders' equity, ending balance		871,396	836,481	871,396		836,481
Noncontrolling Interest [Member]
Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance				36,603		30,884
Purchase of common stock				0	[1]	0	[2]
Other transactions with shareholders	[3]			0		0
Transactions with noncontrolling interests, net						(3,355)
Net Income (Loss) Attributable to Noncontrolling Interest		2,078	5,005
Dividends on common stock				0		0
Stockholders' equity, ending balance		$ 38,681	$ 32,534	$ 38,681		$ 32,534

[1] Represents 133,000 shares purchased in connection with employee tax withholding for restricted stock units vested under our 2012 Equity Incentive Plan.

[2] Represents 109,000 shares purchased in connection with employee tax withholding for restricted stock units vested under our 2012 Equity Incentive Plan.

[3] Amounts are comprised primarily of amortized restricted stock units.