Legal Proceedings	9 Months Ended
Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	Legal Proceedings In the ordinary course of business, we and our affiliates are involved in various legal proceedings that are pending against us and our affiliates alleging, among other things, public liability issues or breach of contract or tortious conduct in connection with the performance of services and/or materials provided, the various outcomes of which cannot be predicted with certainty. We and our affiliates are also subject to government inquiries in the ordinary course of business seeking information concerning our compliance with government construction contracting requirements and related laws and regulations. We record liabilities in our condensed consolidated balance sheets representing our estimated liabilities relating to legal proceedings and government inquiries to the extent that we have concluded such liabilities are probable and the amounts of such liabilities are reasonably estimable. The aggregate liabilities recorded as of September 30, 2013, December 31, 2012, and September 30, 2012 related to these matters were approximately $18.0 million, $8.6 million and $6.8 million, respectively, and were primarily included in accrued expenses and other current liabilities on our condensed consolidated balance sheets. Some of the matters in which we or our affiliates are involved may involve compensatory, punitive, or other claims or sanctions that if granted, could require us to pay damages or make other expenditures in amounts that are not probable to be incurred or cannot currently be reasonably estimated. In addition, in some circumstances our government contracts could be terminated, we could be suspended or debarred, or payment of our costs could be disallowed. While any one of our pending legal proceedings is subject to early resolution as a result of our ongoing efforts to settle, whether or when any legal proceeding will be resolved through settlement is neither predictable nor guaranteed. Accordingly, it is possible that future developments in such proceedings and inquiries could require us to (i) adjust existing accruals, or (ii) record new accruals that we did not originally believe to be probable or that could not be reasonably estimated. Such changes could be material to our financial condition, results of operations and cash flows in any particular reporting period. In addition to matters that are considered probable for which the loss can be reasonably estimated, we also disclose certain matters where the loss is considered reasonably possible and is reasonably estimable. Except as noted below, we believe the aggregate range of possible loss related to matters considered reasonably possible was not material as of September 30, 2013. Our view as to such matters could change in future periods. Investigation Related to Grand Avenue Project Disadvantaged Business Enterprise (“DBE”) Issues: On March 6, 2009, the U.S. Department of Transportation, Office of Inspector General served upon our wholly-owned subsidiary, Granite Construction Northeast, Inc. (“Granite Northeast”), a United States District Court, Eastern District of New York Grand Jury subpoena to produce documents. The subpoena sought all documents pertaining to the use of a DBE firm (the “Subcontractor”), and the Subcontractor’s use of a non-DBE subcontractor/consultant, on the Grand Avenue Bus Depot and Central Maintenance Facility for the Borough of Queens Project (the “Grand Avenue Project”), a Granite Northeast project, that began in 2004 and was substantially complete in 2008. The subpoena sought any documents regarding the use of the Subcontractor as a DBE on any other projects and any other documents related to the Subcontractor or to the subcontractor/consultant. Granite Northeast produced the requested documents, together with other requested information. Subsequently, Granite Northeast was informed by the Department of Justice (“DOJ”) that it is a subject of the investigation, along with others. In January 2013 and October 2013, Granite Northeast met with Assistant United States Attorneys from the DOJ, along with other federal and state agencies (the “Agencies”), to discuss the status of the government’s criminal investigation of the Grand Avenue Project participants, including Granite Northeast. In addition to the documents produced in response to the Grand Jury subpoena, Granite Northeast has provided information to the Agencies concerning other DBE entities for which Granite Northeast has historically claimed DBE credit. The Agencies have informed Granite Northeast that they believe that the claimed DBE credit taken for some of those other DBE entities was improper. If the Agencies prevail in this view, Granite Northeast could be subject to civil, criminal, and/or administrative penalties or sanctions. Granite is unable to estimate at this time the entire liability or the most likely amount of liability that it may incur in connection with this matter. Because Granite believes that the incurrence of some form of penalty or sanction is probable, Granite has recorded the low end of the estimated range of potential liabilities in its condensed consolidated balance sheets as of September 30, 2013. Granite believes the likelihood of liability for amounts in excess of this accrual, up to the amount of the DBE subcontract, is reasonably possible. Under certain circumstances the resolution of the matters under investigation could have direct or indirect consequences that could have a material adverse effect on our financial position, results of operations and/or liquidity.

Legal Proceedings

In the ordinary course of business, we and our affiliates are involved in various legal proceedings that are pending against us and our affiliates alleging, among other things, public liability issues or breach of contract or tortious conduct in connection with the performance of services and/or materials provided, the various outcomes of which cannot be predicted with certainty. We and our affiliates are also subject to government inquiries in the ordinary course of business seeking information concerning our compliance with government construction contracting requirements and related laws and regulations.

We record liabilities in our condensed consolidated balance sheets representing our estimated liabilities relating to legal proceedings and government inquiries to the extent that we have concluded such liabilities are probable and the amounts of such liabilities are reasonably estimable. The aggregate liabilities recorded as of September 30, 2013, December 31, 2012, and September 30, 2012 related to these matters were approximately $18.0 million, $8.6 million and $6.8 million, respectively, and were primarily included in accrued expenses and other current liabilities on our condensed consolidated balance sheets. Some of the matters in which we or our affiliates are involved may involve compensatory, punitive, or other claims or sanctions that if granted, could require us to pay damages or make other expenditures in amounts that are not probable to be incurred or cannot currently be reasonably estimated. In addition, in some circumstances our government contracts could be terminated, we could be suspended or debarred, or payment of our costs could be disallowed. While any one of our pending legal proceedings is subject to early resolution as a result of our ongoing efforts to settle, whether or when any legal proceeding will be resolved through settlement is neither predictable nor guaranteed. Accordingly, it is possible that future developments in such proceedings and inquiries could require us to (i) adjust existing accruals, or (ii) record new accruals that we did not originally believe to be probable or that could not be reasonably estimated. Such changes could be material to our financial condition, results of operations and cash flows in any particular reporting period. In addition to matters that are considered probable for which the loss can be reasonably estimated, we also disclose certain matters where the loss is considered reasonably possible and is reasonably estimable. Except as noted below, we believe the aggregate range of possible loss related to matters considered reasonably possible was not material as of September 30, 2013. Our view as to such matters could change in future periods.

Investigation Related to Grand Avenue Project Disadvantaged Business Enterprise (“DBE”) Issues: On March 6, 2009, the U.S. Department of Transportation, Office of Inspector General served upon our wholly-owned subsidiary, Granite Construction Northeast, Inc. (“Granite Northeast”), a United States District Court, Eastern District of New York Grand Jury subpoena to produce documents. The subpoena sought all documents pertaining to the use of a DBE firm (the “Subcontractor”), and the Subcontractor’s use of a non-DBE subcontractor/consultant, on the Grand Avenue Bus Depot and Central Maintenance Facility for the Borough of Queens Project (the “Grand Avenue Project”), a Granite Northeast project, that began in 2004 and was substantially complete in 2008. The subpoena sought any documents regarding the use of the Subcontractor as a DBE on any other projects and any other documents related to the Subcontractor or to the subcontractor/consultant. Granite Northeast produced the requested documents, together with other requested information. Subsequently, Granite Northeast was informed by the Department of Justice (“DOJ”) that it is a subject of the investigation, along with others. In January 2013 and October 2013, Granite Northeast met with Assistant United States Attorneys from the DOJ, along with other federal and state agencies (the “Agencies”), to discuss the status of the government’s criminal investigation of the Grand Avenue Project participants, including Granite Northeast. In addition to the documents produced in response to the Grand Jury subpoena, Granite Northeast has provided information to the Agencies concerning other DBE entities for which Granite Northeast has historically claimed DBE credit. The Agencies have informed Granite Northeast that they believe that the claimed DBE credit taken for some of those other DBE entities was improper. If the Agencies prevail in this view, Granite Northeast could be subject to civil, criminal, and/or administrative penalties or sanctions. Granite is unable to estimate at this time the entire liability or the most likely amount of liability that it may incur in connection with this matter. Because Granite believes that the incurrence of some form of penalty or sanction is probable, Granite has recorded the low end of the estimated range of potential liabilities in its condensed consolidated balance sheets as of September 30, 2013. Granite believes the likelihood of liability for amounts in excess of this accrual, up to the amount of the DBE subcontract, is reasonably possible. Under certain circumstances the resolution of the matters under investigation could have direct or indirect consequences that could have a material adverse effect on our financial position, results of operations and/or liquidity.