v2.3.0.15

Stockholders' Equity And Stock-Based Compensation (Summary Of Weighted-Average Fair Value Of Stock Options Granted And Total Intrinsic Value Of Stock Options Exercised) (Details) (USD $) In Thousands, except Per Share data | 12 Months Ended
--- | ---
Sep. 30, 2011 | Sep. 24, 2010 | Sep. 25, 2009
Stockholders' Equity And Stock-Based Compensation [Abstract] |  |  |
Weighted-average fair value at date of grant | $ 22.31 | $ 19.93 | $ 14.32
Intrinsic value of options exercised | $ 46,649 | $ 79,453 | $ 29,523
Fair value of options vested | $ 26,442 | $ 20,542 | $ 17,448

X
- Definition Share based compensation arrangement by share based payment fair value of options vested. + Details
Name: | dlb_ShareBasedCompensationArrangementByShareBasedPaymentFairValueOfOptionsVested
Namespace Prefix: | dlb
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Stockholders Equity And Stock-Based Compensation Abstract + Details
Name: | dlb_StockholdersEquityAndStockBasedCompensationAbstract
Namespace Prefix: | dlb
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph c(2) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph c(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration