Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

This information has been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, contains all adjustments necessary for a fair statement thereof.

QUARTERLY FINANCIAL DATA
(unaudited - dollars in thousands, except per share data)
2012 Quarters Ended	December 31,			September 30,			June 30,			March 31,
Revenue	$	504,781		$	728,482		$	539,615		$	310,160
Gross profit	56,808			101,099			51,916			24,936
As a percent of revenue	11.3		%	13.9		%	9.6		%	8.0		%
Net income (loss)1	$	18,374		$	45,746		$	4,487		$	(8,687	)
As a percent of revenue	3.6		%	6.3		%	0.8		%	-2.8		%
Net income (loss) attributable to Granite	$	17,987		$	37,121		$	1,949		$	(11,773	)
As a percent of revenue	3.6		%	5.1		%	0.4		%	-3.8		%
Net income (loss) per share attributable to common shareholders:
Basic	$	0.46		$	0.96		$	0.05		$	(0.31	)
Diluted	$	0.46		$	0.94		$	0.05		$	(0.31	)

2011 Quarters Ended	December 31,			September 30,			June 30,			March 31,
Revenue	$	539,548		$	728,578		$	484,674		$	256,731
Gross profit	79,126			93,893			44,956			29,988
As a percent of revenue	14.7		%	12.9		%	9.3		%	11.7		%
Net (loss) income	$	24,792		$	42,376		$	6,173		$	(7,256	)
As a percent of revenue	4.6		%	5.8		%	1.3		%	-2.8		%
Net (loss) income attributable to Granite	$	18,754		$	36,468		$	4,946		$	(9,007	)
As a percent of revenue	3.5		%	5.0		%	1.0		%	-3.5		%
Net (loss) income per share attributable to common shareholders:
Basic	$	0.48		$	0.94		$	0.13		$	(0.24	)
Diluted	$	0.48		$	0.93		$	0.13		$	(0.24	)