XBRL Cloud: Business Report

Rendering

Component: (Network and Table)
Network	2402402 - Disclosure - Revisions in Estimates (Details) (http://www.graniteconstruction.com/role/RevisionsInEstimatesDetails)
Table	Schedule of Change in Accounting Estimate [Table]

Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]	0000861459 (http://www.sec.gov/CIK)
Joint Venture by Name [Axis]	Joint Venture by Name [Domain]
Legal Entity [Axis]	Entity [Domain]
Scenario [Axis]	Scenario, Unspecified [Domain]

Period [Axis]	Contract By Type [Axis]	Completion Status [Axis]	Change in Accounting Estimate by Type [Axis]	Change in Accounting Estimate [Line Items]	Segments [Axis]
					Construction [Member]			Large Project Construction [Member]				Segments [Domain]
					Range [Axis]			Range [Axis]				Range [Axis]
					Minimum [Member]	Maximum [Member]	Range [Domain]	Minimum [Member]	Maximum [Member]	Range [Domain]		Range [Domain]
					Equity Components [Axis]	Equity Components [Axis]	Equity Components [Axis]	Equity Components [Axis]	Equity Components [Axis]	Equity Components [Axis]		Equity Components [Axis]
					Equity Component [Domain]	Equity Component [Domain]	Equity Component [Domain]	Equity Component [Domain]	Equity Component [Domain]	Noncontrolling Interest [Member]	Equity Component [Domain]	Equity Component [Domain]
2013-10-01 - 2013-12-31	Contract 1 [Member]	Not, Complete or Substantially Complete [Member]	Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete			.852
				Construction Contract Backlog, Percent
	Contract 2 [Member]	Not, Complete or Substantially Complete [Member]	Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete			.862
				Construction Contract Backlog, Percent
	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								49,751,000
				Financial Effect on Future Periods								0
				Amount Considered Significant on Individual Project Gross Profit								1,000,000
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value		75,000,000		75,000,000
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent								.020
2013-07-01 - 2013-09-30	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								55,858,000 ¹
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2013-04-01 - 2013-06-30	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								49,596,000 ²
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2013-01-01 - 2013-12-31	Contract 1 [Member]	Not, Complete or Substantially Complete [Member]	Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete			.852
				Construction Contract Backlog, Percent
	Contract 2 [Member]	Not, Complete or Substantially Complete [Member]	Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete			.862
				Construction Contract Backlog, Percent
	Contract By Type [Domain]	Not, Complete or Substantially Complete [Member]	Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes			2
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
		Complete or Substantially Complete [Member]	Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes			3
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
		Completion Status [Domain]	Upward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold			9,100,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			16,100,000				77,500,000
				Number of Projects with Estimate Changes			6				7
				Total Contract Value
				Range Of Effect On Gross Profit	1,100,000	3,700,000		2,600,000	34,000,000
				Percent Complete
				Construction Contract Backlog, Percent
			Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			(17,800,000)				(52,000,000)
				Number of Projects with Estimate Changes			5				5
				Total Contract Value
				Range Of Effect On Gross Profit	(1,000,000)	(6,900,000)		(1,900,000)	(23,500,000)
				Percent Complete
				Construction Contract Backlog, Percent
			Contracts Accounted for under Percentage of Completion [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
Increase (Decrease) on Project Profitability									(5,600,000)	25,500,000
Number of Projects with Estimate Changes
Total Contract Value
Range Of Effect On Gross Profit
Percent Complete
Construction Contract Backlog, Percent
Change in Accounting Estimate, Type [Domain]			Revenue Recognition, Percentage of Completion, Recognition Threshold								0.25
			Initial gross profit impact from projects exceeding threshold								185,263,000
			Financial Effect on Future Periods								0
			Amount Considered Significant on Individual Project Gross Profit
			Increase (Decrease) on Project Profitability			1,700,000
			Number of Projects with Estimate Changes
			Total Contract Value		75,000,000		75,000,000
			Range Of Effect On Gross Profit
			Percent Complete
			Construction Contract Backlog, Percent								.020
2013-01-01 - 2013-03-31	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								30,058,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2012-10-01 - 2012-12-31	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								56,808,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2012-07-01 - 2012-09-30	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								101,099,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2012-04-01 - 2012-06-30	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								51,916,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2012-01-01 - 2012-12-31	Contract By Type [Domain]	Completion Status [Domain]	Upward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold			16,400,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			8,100,000				92,000,000
				Number of Projects with Estimate Changes			6				10
				Total Contract Value
				Range Of Effect On Gross Profit	1,000,000	1,700,000		1,000,000	24,500,000
				Percent Complete
				Construction Contract Backlog, Percent
			Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			(26,200,000)				(27,400,000)
				Number of Projects with Estimate Changes			9				1
				Total Contract Value
				Range Of Effect On Gross Profit	(1,000,000)	(6,600,000)		(27,400,000)	(27,400,000)
				Percent Complete
				Construction Contract Backlog, Percent
			Contracts Accounted for under Percentage of Completion [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability						3,100,000	64,600,000
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
			Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								234,759,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit								1,000,000
				Increase (Decrease) on Project Profitability			18,100,000
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2012-01-01 - 2012-03-31	Contract By Type [Domain]	Completion Status [Domain]	Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								24,936,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
2011-01-01 - 2011-12-31	Contract By Type [Domain]	Completion Status [Domain]	Upward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold			55,400,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			13,600,000				28,300,000
				Number of Projects with Estimate Changes			7				9
				Total Contract Value
				Range Of Effect On Gross Profit	1,000,000	3,500,000		1,100,000	6,900,000
				Percent Complete
				Construction Contract Backlog, Percent
			Downward Estimate Change [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			(7,400,000)				(19,400,000)
				Number of Projects with Estimate Changes			4				5
				Total Contract Value
				Range Of Effect On Gross Profit	(1,400,000)	(2,600,000)		(1,200,000)	(5,100,000)
				Percent Complete
				Construction Contract Backlog, Percent
			Contracts Accounted for under Percentage of Completion [Member]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability						2,800,000	8,900,000
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent
			Change in Accounting Estimate, Type [Domain]	Revenue Recognition, Percentage of Completion, Recognition Threshold
				Initial gross profit impact from projects exceeding threshold								247,963,000
				Financial Effect on Future Periods
				Amount Considered Significant on Individual Project Gross Profit
				Increase (Decrease) on Project Profitability			6,200,000
				Number of Projects with Estimate Changes
				Total Contract Value
				Range Of Effect On Gross Profit
				Percent Complete
				Construction Contract Backlog, Percent

1: Net income for the quarter ended September 30 is approximately $2.1 million ($3.0 million pre-tax) higher than the amount previously reported in our Quarterly Report Form 10-Q for the quarterly period ended September 30, 2013 of $4.5 million. The pre-tax adjustments were primarily related to (i) an over-accrual of pre-bid costs which affected selling, general and administrative expenses and accrued and other current liabilities in the amount of $1.4 million and (ii) a revision in equipment-related costs, which affected cost of revenue and property and equipment in the amount of $1.6 million.
2: Net income for the quarter ended June 30 is approximately $1.4 million ($1.9 million pre-tax) lower than the amounts previously reported in our Form 10-Q for the quarter period ended June 30, 2013 of $3.2 million. The pre-tax adjustments were primarily related to equipment-related costs of $1.7 million.