Earnings Per Share (Details) (USD $) In Thousands, except Per Share data	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Earnings Per Share, Basic, Two Class Method [Abstract]
Net income (loss) attributable to Granite, Earnings Per Share, Basic	$ 4,946	$ (6,691)	$ (4,061)	$ (47,645)
Participating Securities, Distributed and Undistributed Earnings	65	0	0	0
Net Income (Loss) Available to Common Stockholders, Basic	4,881	(6,691)	(4,061)	(47,645)
Weighted Average Number of Shares Outstanding, Basic	38,140	37,850	38,052	37,770
Net income (loss) per share, basic	$ 0.13	$ (0.18)	$ (0.11)	$ (1.26)
Earnings Per Share, Diluted, Two Class Method [Abstract]
Net income (loss) attributable to Grainte, Earnings per Share, Diluted	4,946	(6,691)	(4,061)	(47,645)
Participating Securities, Distributed and Undistributed Earnings	65	0	0	0
Net Income (Loss) Available to Common Stockholders, Diluted	$ 4,881	$ (6,691)	$ (4,061)	$ (47,645)
Weighted average common shares outstanding, diluted	38,479	37,850	38,052	37,770
Net income (loss) per share, diluted	$ 0.13	$ (0.18)	$ (0.11)	$ (1.26)

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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