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This item represents the fair value of debt securities which are expected to mature after one year and through two years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

No definition available.

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This item represents debt securities, at cost, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments, as defined), and fair value hedge accounting adjustments, if any, which are expected to mature after two year and through three years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

No definition available.

Name:	dlb_AvailableForSaleSecuritiesDebtMaturitiesAfterTwoThroughThreeYearsAmortizedCost
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This item represents the fair value of debt securities which are expected to mature after two year and through three years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

No definition available.

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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).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References

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No definition available.

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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), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Name:	us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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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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