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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.

Name:	rmbs_CashCashEquivalentsAndShortTermInvestmentsAmortizedCostDisclosure
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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
Balance Type:	debit
Period Type:	instant

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
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

No definition available.

Name:	rmbs_GrossUnrealizedGainOnSecuritiesAndCash
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

This item represents the gross unrealized losses for cash, cash equivalents and marketable securities.

No definition available.

Name:	rmbs_GrossUnrealizedLossOnSecuritiesAndCash
Namespace Prefix:	rmbs_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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

No definition available.

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

-- None. No documentation exists for this element. --

No definition available.

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Namespace Prefix:	rmbs_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- References

No definition available.