Per Share Data (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 27, 2015	Dec. 26, 2014	Mar. 28, 2014	Dec. 27, 2013	Mar. 27, 2015	Mar. 28, 2014
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income attributable to Dolby Laboratories, Inc.		$ 57,974us-gaap_NetIncomeLoss		$ 75,868us-gaap_NetIncomeLoss	$ 99,331us-gaap_NetIncomeLoss	$ 120,383us-gaap_NetIncomeLoss
Weighted average shares outstanding-basic		102,509		102,291	102,406	102,021
Potential common shares from options to purchase common stock		889		637	941	445
Potential common shares from restricted stock units		506		1,006	750	994
Weighted average shares outstanding-diluted	103,904	103,904	103,934	103,934	104,097	103,460
Net income per share attributable to Dolby Laboratories, Inc. - Basic (in usd per share)		$ 0.57us-gaap_EarningsPerShareBasic		$ 0.74us-gaap_EarningsPerShareBasic	$ 0.97us-gaap_EarningsPerShareBasic	$ 1.18us-gaap_EarningsPerShareBasic
Net income per share attributable to Dolby Laboratories, Inc. - Diluted (in usd per share)		$ 0.56us-gaap_EarningsPerShareDiluted		$ 0.73us-gaap_EarningsPerShareDiluted	$ 0.95us-gaap_EarningsPerShareDiluted	$ 1.16us-gaap_EarningsPerShareDiluted
Stock Options [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Anti-dilutive securities, excluded from calculations (in shares)		4,604		3,597	3,684	4,075
Restricted Stock Units [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Anti-dilutive securities, excluded from calculations (in shares)		934		290	106	1,170

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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