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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.

No definition available.

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Data Type:	xbrli:monetaryItemType
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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.

No definition available.

Name:	rmbs_CashCashEquivalentsAndShortTermInvestmentsFairValueDisclosure
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
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Cash Cash Equivalents And Short Term Investments Unrealized Gains

No definition available.

Name:	rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedGains
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
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Cash Cash Equivalents And Short Term Investments Unrealized Losses

No definition available.

Name:	rmbs_CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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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.

No definition available.

Name:	rmbs_CashFairValueDisclosure
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This item represents the gross unrealized gains for cash, cash equivalents and marketable securities

No definition available.

Name:	rmbs_GrossUnrealizedGainOnSecuritiesAndCash
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Data Type:	xbrli:monetaryItemType
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This item represents the gross unrealized losses for cash, cash equivalents and marketable securities.

No definition available.

Name:	rmbs_GrossUnrealizedLossOnSecuritiesAndCash
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Data Type:	xbrli:monetaryItemType
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Represents the maximum maturity period of securities invested by the entity.

No definition available.

Name:	rmbs_MaximumMaturityPeriodAvailableForSaleSecurities
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Period Type:	duration

Represents the maximum remaining maturity period of securities invested by the entity.

No definition available.

Name:	rmbs_MaximumRemainingMaturityPeriodAvailableForSaleSecurities
Namespace Prefix:	rmbs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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Data Type:	xbrli:stringItemType
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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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.

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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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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-Publisher SEC

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