CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Noncontrolling Interests [Member]	Total Granite Shareholders' Equity [Member]	Retained Earnings [Member]	Additional Paid-in Capital [Member]	AOCI Including Portion Attributable to Noncontrolling Interest [Member]	Common Stock [Member]
Beginning Balance at Dec. 31, 2013	$ 786,344	$ 4,404	$ 781,940	$ 655,102	$ 126,444	$ 5	$ 389
Beginning Balance (in shares) at Dec. 31, 2013							38,917,728
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	35,876	10,530			0	0	$ 0
Net Income (Loss) Attributable to Parent	25,346		25,346	25,346
Other comprehensive income (loss)	(433)	0	(433)		0	(433)	0
Stock units vested	4	0	4	0	0	0	$ 4
Stock units vested (in shares)							378,027
Amortized restricted stock units	11,160	0	11,160	0	11,160	0	$ 0
Purchase of common stock	(5,187)	0	(5,187)	0	(5,186)	0	$ (1)
Purchase of common stock (in shares)							(135,028)
Cash dividends on common stock	(20,354)	0	(20,354)	(20,354)	0	0	$ 0
Net tax on stock-based compensation	1,080	0	1,080	0	1,080	0	0
Transactions with noncontrolling interests, net	7,787	7,787	0	0	0	0	0
Stock options exercised and other	829	0	829	(278)	1,107	0	$ 0
Stock options exercised and other (in shares)							25,659
Ending Balance at Dec. 31, 2014	817,106	22,721	794,385	659,816	134,605	(428)	$ 392
Ending Balance (in shares) at Dec. 31, 2014							39,186,386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	68,248	7,763			0	0	$ 0
Net Income (Loss) Attributable to Parent	60,485		60,485	60,485
Other comprehensive income (loss)	(1,072)	0	(1,072)	0	0	(1,072)	0
Stock units vested	3	0	3	0	0	0	$ 3
Stock units vested (in shares)							317,524
Amortized restricted stock units	8,763	0	8,763	0	8,763	0	$ 0
Purchase of common stock	(3,856)	0	(3,856)	0	(3,855)	0	$ (1)
Purchase of common stock (in shares)							(114,969)
Cash dividends on common stock	(20,476)	0	(20,476)	(20,476)	0	0	$ 0
Transactions with noncontrolling interests, net	400	(400)	0	0	0	0	0
Stock options exercised and other	1,005	0	1,005	(394)	1,399	0	$ 0
Stock options exercised and other (in shares)							23,936
Ending Balance at Dec. 31, 2015	$ 870,121	30,884	839,237	699,431	140,912	(1,500)	$ 394
Ending Balance (in shares) at Dec. 31, 2015	39,412,877						39,412,877
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 66,200	9,078			0		$ 0
Net Income (Loss) Attributable to Parent	57,122		57,122	57,122
Other comprehensive income (loss)	1,129	0	1,129	0	0	1,129	0
Stock units vested	3	0	3	0	0		$ 3
Stock units vested (in shares)							308,619
Amortized restricted stock units	13,383	0	13,383	0	13,383		$ 0
Purchase of common stock	(5,227)	0	(5,227)	0	(5,226)		$ (1)
Purchase of common stock (in shares)							(116,355)
Cash dividends on common stock	(20,590)	0	(20,590)	(20,590)	0		$ 0
Transactions with noncontrolling interests, net	3,359	3,359	0	0	0	0	0
Stock options exercised and other	931	0	931	(337)	1,268	0	$ 0
Stock options exercised and other (in shares)							15,999
Ending Balance at Dec. 31, 2016	$ 922,591	$ 36,603	$ 885,988	$ 735,626	$ 150,337	$ (371)	$ 396
Ending Balance (in shares) at Dec. 31, 2016	39,621,140						39,621,140