CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Noncontrolling Interests [Member]	Total Granite Shareholders' Equity [Member]	Retained Earnings [Member]	Additional Paid-in Capital [Member]	Common Stock [Member]
Beginning Balance at Dec. 31, 2011	$ 827,663	$ 28,466	$ 799,197	$ 687,296	$ 111,514	$ 387
Beginning Balance (in shares) at Dec. 31, 2011						38,682,771
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	59,920	14,637	45,283	45,283	0	0
Stock units vested	1	0	1	0	(1)	2
Stock units vested (in shares)						191,285
Amortized restricted stock	11,475	0	11,475	0	11,475	0
Purchase of common stock	(4,854)	0	(4,854)	0	(4,852)	(2)
Purchase of common stock (in shares)						(161,080)
Cash dividends on common stock	(20,117)	0	(20,117)	(20,117)	0	0
Net tax on stock-based compensation	(1,573)	0	(1,573)	0	(1,573)	0
Noncontrolling interest from acquisition	14,788	14,788	0	0	0	0
Transactions with noncontrolling interests, net	(15,986)	(15,986)	0	0	0	0
Stock options exercised and other	541	0	541	(318)	859	0
Stock options exercised and other (in shares)						17,689
Ending Balance at Dec. 31, 2012	871,858	41,905	829,953	712,144	117,422	387
Ending Balance (in shares) at Dec. 31, 2012						38,730,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(44,766)	(8,343)	(36,423)	(36,423)	0	0
Stock units vested	0	0	0	0	(4)	4
Stock units vested (in shares)						359,941
Amortized restricted stock	13,443	0	13,443	0	13,443	0
Purchase of common stock	(5,902)	0	(5,902)	0	(5,900)	(2)
Purchase of common stock (in shares)						(197,313)
Cash dividends on common stock	(20,210)	0	(20,210)	(20,210)	0	0
Net tax on stock-based compensation	419	0	419	0	419	0
Noncontrolling interest from acquisition					0
Transactions with noncontrolling interests, net	(29,158)	(29,158)	0	0		0
Stock options exercised and other	660	0	660	(409)	1,069	0
Stock options exercised and other (in shares)						24,435
Ending Balance at Dec. 31, 2013	786,344	4,404	781,940	655,102	126,449	389
Ending Balance (in shares) at Dec. 31, 2013	38,917,728					38,917,728
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	35,876	10,530	25,346	25,346	0	0
Stock units vested	4	0	4	0	0	4
Stock units vested (in shares)						378,027
Amortized restricted stock	11,160	0	11,160	0	11,160	0
Purchase of common stock	(5,187)	0	(5,187)	0	(5,186)	(1)
Purchase of common stock (in shares)						(135,028)
Cash dividends on common stock	(20,354)	0	(20,354)	(20,354)	0	0
Net tax on stock-based compensation	1,080	0	1,080	0	1,080	0
Transactions with noncontrolling interests, net	7,787	7,787	0	0	0	0
Stock options exercised and other	396	0	396	(278)	674	0
Stock options exercised and other (in shares)						25,659
Ending Balance at Dec. 31, 2014	$ 817,106	$ 22,721	$ 794,385	$ 659,816	$ 134,177	$ 392
Ending Balance (in shares) at Dec. 31, 2014	39,186,386					39,186,386