Income Taxes	6 Months Ended
Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded a provision for income taxes of $5.8 million and $6.4 million for the three months ended June 30, 2015 and 2014, respectively, and $11.2 million and $11.9 million for the six months ended June 30, 2015 and 2014, respectively. The provision for income taxes for the three and six months ended June 30, 2015 and 2014 is primarily comprised of withholding taxes, state taxes and other foreign taxes. During the three and six months ended June 30, 2015, the Company paid withholding taxes of $4.8 million and $9.6 million. During the three and six months ended June 30, 2014, the Company paid withholding taxes of $4.8 million and $9.8 million, respectively. As of June 30, 2015, the Company’s condensed consolidated balance sheets included net deferred tax assets, before valuation allowance, of approximately $186.5 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 notes. As of June 30, 2015, a full valuation allowance has been recorded against the U.S. deferred tax assets. 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 full valuation allowance on its deferred tax assets in the United States as of June 30, 2015. The Company emerged from a cumulative loss position over the previous three years during the first quarter of 2015. However, given economic uncertainties and the uncertainty of commercializing new business arrangements and new product acceptances, the Company currently believes there is not sufficient positive evidence of sustained future profitability to change its judgment regarding the need for a full valuation allowance on its deferred tax assets in the United States. The continued improvement in the Company's operating results, along with successfully commercializing new business arrangements, signing new or renewing existing license agreements and managing costs would provide additional positive evidence in determining the need for the valuation allowance and could lead to reversal of substantially all of the Company's valuation allowance on its deferred tax assets in the United States. 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 net 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 June 30, 2015, the Company had approximately $20.6 million of unrecognized tax benefits, including $18.4 million recorded as a reduction of long-term deferred tax assets and $2.2 million in long-term income taxes payable. If recognized, approximately $2.2 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, 2014, the Company had $19.9 million of unrecognized tax benefits, including $17.8 million recorded as a reduction of long-term deferred tax assets and $2.1 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 June 30, 2015 and December 31, 2014, 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 ended March 2006 and forward. The Company is currently under examination by California for the 2010 and 2011 tax years. The Company’s India subsidiary is under examination by the Indian tax administration for years 2008 through 2010. These examinations may result in proposed adjustments to the income taxes as filed during these periods. 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. 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 $5.8 million and $6.4 million for the three months ended June 30, 2015 and 2014, respectively, and $11.2 million and $11.9 million for the six months ended June 30, 2015 and 2014, respectively. The provision for income taxes for the three and six months ended June 30, 2015 and 2014 is primarily comprised of withholding taxes, state taxes and other foreign taxes.

During the three and six months ended June 30, 2015, the Company paid withholding taxes of $4.8 million and $9.6 million. During the three and six months ended June 30, 2014, the Company paid withholding taxes of $4.8 million and $9.8 million, respectively.

As of June 30, 2015, the Company’s condensed consolidated balance sheets included net deferred tax assets, before valuation allowance, of approximately $186.5 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 notes. As of June 30, 2015, a full valuation allowance has been recorded against the U.S. deferred tax assets.

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 full valuation allowance on its deferred tax assets in the United States as of June 30, 2015. The Company emerged from a cumulative loss position over the previous three years during the first quarter of 2015. However, given economic uncertainties and the uncertainty of commercializing new business arrangements and new product acceptances, the Company currently believes there is not sufficient positive evidence of sustained future profitability to change its judgment regarding the need for a full valuation allowance on its deferred tax assets in the United States. The continued improvement in the Company's operating results, along with successfully commercializing new business arrangements, signing new or renewing existing license agreements and managing costs would provide additional positive evidence in determining the need for the valuation allowance and could lead to reversal of substantially all of the Company's valuation allowance on its deferred tax assets in the United States. 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 net 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 June 30, 2015, the Company had approximately $20.6 million of unrecognized tax benefits, including $18.4 million recorded as a reduction of long-term deferred tax assets and $2.2 million in long-term income taxes payable. If recognized, approximately $2.2 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, 2014, the Company had $19.9 million of unrecognized tax benefits, including $17.8 million recorded as a reduction of long-term deferred tax assets and $2.1 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 June 30, 2015 and December 31, 2014, 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 ended March 2006 and forward. The Company is currently under examination by California for the 2010 and 2011 tax years. The Company’s India subsidiary is under examination by the Indian tax administration for years 2008 through 2010. These examinations may result in proposed adjustments to the income taxes as filed during these periods. 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.

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.