Income Taxes	3 Months Ended
Mar. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded a provision for income taxes of $5.5 million and $4.5 million for the three months ended March 31, 2014 and 2013, respectively. The provision for income taxes for the three months ended March 31, 2014 and 2013 is primarily comprised of withholding taxes, state taxes and other foreign taxes based upon income earned during the period. During the three months ended March 31, 2014 and 2013, the Company paid withholding taxes of $5.1 million and $3.8 million, respectively. As of March 31, 2014, the Company’s condensed consolidated balance sheets included net deferred tax assets, before valuation allowance, of approximately $188.7 million, which consists of net operating loss carryovers, tax credit carryovers, amortization, employee stock-based compensation expenses and certain liabilities, partially reduced by deferred tax liabilities associated with the convertible debt instruments. As of March 31, 2014, a full valuation allowance has been recorded against the U.S. deferred tax assets. The Company’s deferred tax assets decrease during the three months ended March 31, 2014 is primarily due to the utilization of U.S. tax attribute carryforward. Management periodically evaluates the realizability of the Company's net deferred tax assets based on all available evidence, both positive and negative. The realization of net deferred tax assets is dependent on the Company's ability to generate sufficient future taxable income during periods prior to the expiration of tax attributes to fully utilize these assets. The Company weighed both positive and negative evidence and determined that there is a continued need for a valuation allowance as the Company is in a cumulative loss position over the previous three years, which is considered significant negative evidence. A sustained period of profitability in the Company's operations is required before the Company would change its judgment regarding the need for a full valuation allowance against its net deferred tax assets. Although the weight of negative evidence related to cumulative losses has decreased as the Company has settled outstanding litigation, the Company believes that this objectively measured negative evidence outweighs the subjectively determined positive evidence of future profitability and, as such, the Company has not changed its judgment regarding the need for a full valuation allowance on its deferred tax assets in the United States as of March 31, 2014. However, continued improvement in the Company's operating results, conditioned on its MID, LDT or CRI reporting units successfully commercializing new business arrangements, signing new or renewing existing license agreements and managing costs, could lead to reversal of almost all of the Company's valuation allowance as early as the remainder of 2014. Until such time, consumption of tax attributes to offset profits will reduce the overall level of deferred tax assets subject to valuation allowance. Should the Company determine that it would be able to realize its remaining deferred tax assets in the foreseeable future, an adjustment to its remaining deferred tax assets would cause a material increase to income in the period such determination is made. The Company maintains liabilities for uncertain tax positions within its long-term income taxes payable accounts and as a reduction to existing deferred tax assets to the extent tax attributes are available to offset such liabilities. These liabilities involve judgment and estimation and are monitored by management based on the best information available including changes in tax regulations, the outcome of relevant court cases and other information. As of March 31, 2014, the Company had approximately $20.0 million of unrecognized tax benefits, including $18.0 million recorded as a reduction of long-term deferred tax assets and $2.0 million in long-term income taxes payable. If recognized, approximately $2.0 million would be recorded as an income tax benefit. No benefit would be recorded for the remaining unrecognized tax benefits as the recognition would require a corresponding increase in the valuation allowance. As of December 31, 2013, the Company had $18.8 million of unrecognized tax benefits, including $12.6 million recorded as a reduction of long-term deferred tax assets and $6.2 million recorded in long-term income taxes payable. Although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months, the Company cannot reasonably estimate the outcome at this time. The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision. At March 31, 2014 and December 31, 2013, an immaterial amount of interest and penalties is included in long-term income taxes payable. Rambus files income tax returns for the U.S., California, India and various other state and foreign jurisdictions. The U.S. federal returns are subject to examination from 2012 and forward. The California returns are subject to examination from 2009 and forward. In addition, any research and development credit carryforward or net operating loss carryforward generated in prior years and utilized in these or future years may also be subject to examination. The India returns are subject to examination from fiscal year ending March 2006 and forward. The Company is currently under examination by California for the 2010 and 2011 tax years and by India for fiscal years ending March 2006, 2009 and 2010. Management regularly assesses the likelihood of outcomes resulting from income tax examinations to determine the adequacy of their provision for income taxes and believes their provision for unrecognized tax benefits is adequate. In January 2014, an Internal Revenue Service examination covering the 2010 through 2011 tax years was completed with no audit adjustments. Additionally, the Company's future effective tax rates could be adversely affected by earnings being higher than anticipated in countries where the Company has higher statutory rates or lower than anticipated in countries where it has lower statutory rates, by changes in valuation of its deferred tax assets and liabilities or by changes in tax laws or interpretations of those laws.

Income Taxes

The Company recorded a provision for income taxes of $5.5 million and $4.5 million for the three months ended March 31, 2014 and 2013, respectively. The provision for income taxes for the three months ended March 31, 2014 and 2013 is primarily comprised of withholding taxes, state taxes and other foreign taxes based upon income earned during the period.

During the three months ended March 31, 2014 and 2013, the Company paid withholding taxes of $5.1 million and $3.8 million, respectively.

As of March 31, 2014, the Company’s condensed consolidated balance sheets included net deferred tax assets, before valuation allowance, of approximately $188.7 million, which consists of net operating loss carryovers, tax credit carryovers, amortization, employee stock-based compensation expenses and certain liabilities, partially reduced by deferred tax liabilities associated with the convertible debt instruments. As of March 31, 2014, a full valuation allowance has been recorded against the U.S. deferred tax assets. The Company’s deferred tax assets decrease during the three months ended March 31, 2014 is primarily due to the utilization of U.S. tax attribute carryforward.

Management periodically evaluates the realizability of the Company's net deferred tax assets based on all available evidence, both positive and negative. The realization of net deferred tax assets is dependent on the Company's ability to generate sufficient future taxable income during periods prior to the expiration of tax attributes to fully utilize these assets. The Company weighed both positive and negative evidence and determined that there is a continued need for a valuation allowance as the Company is in a cumulative loss position over the previous three years, which is considered significant negative evidence. A sustained period of profitability in the Company's operations is required before the Company would change its judgment regarding the need for a full valuation allowance against its net deferred tax assets. Although the weight of negative evidence related to cumulative losses has decreased as the Company has settled outstanding litigation, the Company believes that this objectively measured negative evidence outweighs the subjectively determined positive evidence of future profitability and, as such, the Company has not changed its judgment regarding the need for a full valuation allowance on its deferred tax assets in the United States as of March 31, 2014. However, continued improvement in the Company's operating results, conditioned on its MID, LDT or CRI reporting units successfully commercializing new business arrangements, signing new or renewing existing license agreements and managing costs, could lead to reversal of almost all of the Company's valuation allowance as early as the remainder of 2014. Until such time, consumption of tax attributes to offset profits will reduce the overall level of deferred tax assets subject to valuation allowance. Should the Company determine that it would be able to realize its remaining deferred tax assets in the foreseeable future, an adjustment to its remaining deferred tax assets would cause a material increase to income in the period such determination is made.

The Company maintains liabilities for uncertain tax positions within its long-term income taxes payable accounts and as a reduction to existing deferred tax assets to the extent tax attributes are available to offset such liabilities. These liabilities involve judgment and estimation and are monitored by management based on the best information available including changes in tax regulations, the outcome of relevant court cases and other information.

As of March 31, 2014, the Company had approximately $20.0 million of unrecognized tax benefits, including $18.0 million recorded as a reduction of long-term deferred tax assets and $2.0 million in long-term income taxes payable. If recognized, approximately $2.0 million would be recorded as an income tax benefit. No benefit would be recorded for the remaining unrecognized tax benefits as the recognition would require a corresponding increase in the valuation allowance. As of December 31, 2013, the Company had $18.8 million of unrecognized tax benefits, including $12.6 million recorded as a reduction of long-term deferred tax assets and $6.2 million recorded in long-term income taxes payable.

Although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months, the Company cannot reasonably estimate the outcome at this time.

The Company recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision. At March 31, 2014 and December 31, 2013, an immaterial amount of interest and penalties is included in long-term income taxes payable.

Rambus files income tax returns for the U.S., California, India and various other state and foreign jurisdictions. The U.S. federal returns are subject to examination from 2012 and forward. The California returns are subject to examination from 2009 and forward. In addition, any research and development credit carryforward or net operating loss carryforward generated in prior years and utilized in these or future years may also be subject to examination. The India returns are subject to examination from fiscal year ending March 2006 and forward. The Company is currently under examination by California for the 2010 and 2011 tax years and by India for fiscal years ending March 2006, 2009 and 2010. Management regularly assesses the likelihood of outcomes resulting from income tax examinations to determine the adequacy of their provision for income taxes and believes their provision for unrecognized tax benefits is adequate. In January 2014, an Internal Revenue Service examination covering the 2010 through 2011 tax years was completed with no audit adjustments.

Additionally, the Company's future effective tax rates could be adversely affected by earnings being higher than anticipated in countries where the Company has higher statutory rates or lower than anticipated in countries where it has lower statutory rates, by changes in valuation of its deferred tax assets and liabilities or by changes in tax laws or interpretations of those laws.