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v2.4.1.9

Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013
Cash equivalents and marketable securities |  |
Fair Value | $ 270,921 us-gaap_AvailableForSaleSecurities | $ 359,097 us-gaap_AvailableForSaleSecurities
Amortized Cost | 271,034 us-gaap_AvailableForSaleSecuritiesAmortizedCost | 359,112 us-gaap_AvailableForSaleSecuritiesAmortizedCost
Cash Cash Equivalents And Short Term Investments Unrealized Gains | 1 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains | 0 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses | 114 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses | 15 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses
Gross Unrealized Gains | 1 rmbs_GrossUnrealizedGainOnSecuritiesAndCash | 0 rmbs_GrossUnrealizedGainOnSecuritiesAndCash
Gross Unrealized Losses | 114 rmbs_GrossUnrealizedLossOnSecuritiesAndCash | 15 rmbs_GrossUnrealizedLossOnSecuritiesAndCash
Cash, fair value | 29,188 rmbs_CashFairValueDisclosure | 28,565 rmbs_CashFairValueDisclosure
Cash | 29,188 us-gaap_Cash | 28,565 us-gaap_Cash
Cash, cash equivalents and marketable securities |  |
Fair Value | 300,109 rmbs_CashCashEquivalentsAndShortTermInvestmentsFairValueDisclosure | 387,662 rmbs_CashCashEquivalentsAndShortTermInvestmentsFairValueDisclosure
Amortized Cost | 300,222 rmbs_CashCashEquivalentsAndShortTermInvestmentsAmortizedCostDisclosure | 387,677 rmbs_CashCashEquivalentsAndShortTermInvestmentsAmortizedCostDisclosure
Money market funds |  |
Cash equivalents and marketable securities |  |
Fair Value | 124,938 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember | 300,605 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember
Amortized Cost | 124,938 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember | 300,605 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember
Cash Cash Equivalents And Short Term Investments Unrealized Gains | 0 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember | 0 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses | 0 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember | 0 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember
Weighted Rate of Return (as a percent) | 0.01%rmbs_AvailableForSaleSecuritiesWeightedRateOfReturn / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember | 0.01%rmbs_AvailableForSaleSecuritiesWeightedRateOfReturn / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MoneyMarketFundsMember
Corporate notes, bonds and commercial paper |  |
Cash equivalents and marketable securities |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 139,989 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | 53,491 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
Maximum maturity period of available-for-sale securities (in years) | 3 years |
Maximum remaining maturity period of available-for-sale securities (in years) | 1 year |
Fair Value | 145,983 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | 58,492 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
Amortized Cost | 146,096 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | 58,507 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
Cash Cash Equivalents And Short Term Investments Unrealized Gains | 1 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | 0 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses | 114 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | 15 rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
Weighted Rate of Return (as a percent) | 0.25%rmbs_AvailableForSaleSecuritiesWeightedRateOfReturn / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | 0.15%rmbs_AvailableForSaleSecuritiesWeightedRateOfReturn / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
Unrealized gain (loss), net |  |
Less than one year, Gross unrealized loss | (114)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember | (15)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember
Cash equivalents |  |
Cash equivalents and marketable securities |  |
Maximum remaining maturity period of available-for-sale securities (in years) | 1 year |
Fair Value | 124,938 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashEquivalentsMember | 310,131 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashEquivalentsMember
Short term marketable securities |  |
Cash equivalents and marketable securities |  |
Fair Value | $ 145,983 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember | $ 48,966 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember

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- Definition This item represents the amortized cost of cash, cash equivalents and marketable securities, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
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- Definition This element represents the aggregate of cash, cash equivalents and marketable securities reported on the balance sheet at period end measured at fair value by the entity. + References No definition available. + Details
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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the company may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. + References No definition available. + Details
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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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