CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	Total	Total Granite Shareholders' Equity [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2008	$ 804,282	$ 767,509	$ 383	$ 85,035	$ 682,237	$ (146)	$ 36,773
Beginning Balance (in shares) at Dec. 31, 2008			38,266,791
Comprehensive income:
Net income (loss)	100,201	73,500	0	0	73,500	0	26,701
Changes in net unrealized gains on investments		146	0	0	0	146	0
Total comprehensive income	100,347
Restricted stock and stock issued for services (in 2009 and 2010) / Stock units vested for services (in 2011), net of forfeitures	1,904	1,904	4	1,900	0	0	0
Restricted stock and stock issued for services (in 2009 and 2010) / Stock units vested for services (in 2011), net of forfeitures (in shares)			437,594
Amortized restricted stock	10,765	10,765	0	10,765	0	0	0
Purchase of common stock	(3,431)	(3,431)	(1)	(3,430)	0	0	0
Purchase of common stock (in shares)	0		(93,763)
Cash dividends on common stock	(20,105)	(20,105)	0	0	(20,105)	0	0
Net tax on stock-based compensation	632	632	0	632	0	0	0
Transactions with noncontrolling interests, net	(11,569)	0	0	0	0	0	(11,569)
Stock options exercised and other	(269)	(269)	0	(269)	0	0	0
Stock options exercised and other (in shares)			24,399
Ending Balance at Dec. 31, 2009	882,556	830,651	386	94,633	735,632	0	51,905
Ending Balance (in shares) at Dec. 31, 2009			38,635,021
Comprehensive income:
Net income (loss)	(62,448)	(58,983)	0	0	(58,983)	0	(3,465)
Total comprehensive income	(62,448)
Restricted stock and stock issued for services (in 2009 and 2010) / Stock units vested for services (in 2011), net of forfeitures	1,005	1,005	2	1,003	0	0	0
Restricted stock and stock issued for services (in 2009 and 2010) / Stock units vested for services (in 2011), net of forfeitures (in shares)			214,128
Amortized restricted stock	13,040	13,040	0	13,040	0	0	0
Purchase of common stock	(3,641)	(3,641)	(1)	(3,640)	0	0	0
Purchase of common stock (in shares)	0		(132,093)
Cash dividends on common stock	(20,165)	(20,165)	0	0	(20,165)	0	0
Net tax on stock-based compensation	(815)	(815)	0	(815)	0	0	0
Transactions with noncontrolling interests, net	(13,836)	0	0	0	0	0	(13,836)
Stock options exercised and other	(61)	(61)	0	11	(72)	0	0
Stock options exercised and other (in shares)			28,486
Ending Balance at Dec. 31, 2010	795,635	761,031	387	104,232	656,412	0	34,604
Ending Balance (in shares) at Dec. 31, 2010	38,745,542		38,745,542
Comprehensive income:
Net income (loss)	66,085	51,161	0	0	51,161	0	14,924
Total comprehensive income	66,085
Restricted stock and stock issued for services (in 2009 and 2010) / Stock units vested for services (in 2011), net of forfeitures	0	0	1	(1)	0	0	0
Restricted stock and stock issued for services (in 2009 and 2010) / Stock units vested for services (in 2011), net of forfeitures (in shares)			80,245
Amortized restricted stock	12,155	12,155	0	12,155	0	0	0
Purchase of common stock	(4,029)	(4,029)	(1)	(4,028)	0	0	0
Purchase of common stock (in shares)	0		(143,527)
Cash dividends on common stock	(20,107)	(20,107)	0	0	(20,107)	0	0
Net tax on stock-based compensation	(1,360)	(1,360)	0	(1,360)	0	0	0
Transactions with noncontrolling interests, net	(21,062)	0	0	0	0	0	(21,062)
Stock options exercised and other	346	346	0	516	(170)	0	0
Stock options exercised and other (in shares)			511
Ending Balance at Dec. 31, 2011	$ 827,663	$ 799,197	$ 387	$ 111,514	$ 687,296	$ 0	$ 28,466
Ending Balance (in shares) at Dec. 31, 2011	38,682,771		38,682,771