Summary Of Significant Accounting Policies (Policy)	6 Months Ended
Mar. 30, 2018
Accounting Policies [Abstract]
Principles Of Consolidation	Principles of Consolidation The unaudited interim condensed consolidated financial statements include the accounts of Dolby Laboratories, Inc. and our wholly owned subsidiaries. In addition, we have consolidated the financial results of jointly owned affiliated companies in which our principal stockholder has a controlling interest. We report these controlling interests as a separate line in our consolidated statements of operations as net income attributable to controlling interest and in our consolidated balance sheets as a controlling interest. We eliminate all intercompany accounts and transactions upon consolidation.
Operating Segments	Operating Segments Since we operate as a single reporting segment, all required financial segment information is included in our unaudited interim condensed consolidated financial statements. This determination reflects the fact that our CODM, our Chief Executive Officer, evaluates our financial information and resources, and assesses the performance of these resources on a consolidated basis.
Use of Estimates	Use of Estimates The preparation of our financial statements in accordance with U.S. GAAP requires management to make certain estimates and assumptions that affect the amounts reported and disclosed in our unaudited interim condensed consolidated financial statements and accompanying notes. Significant items subject to such estimates and assumptions include estimated selling prices for elements sold in ME revenue arrangements; valuation allowances for accounts receivable; carrying values of inventories and certain property, plant, and equipment, goodwill and intangible assets; fair values of investments; accrued liabilities including liabilities for unrecognized tax benefits, deferred income tax assets and liabilities, and stock-based compensation. Actual results could differ from our estimates.
Fiscal Year	Fiscal Year Our fiscal year is a 52 or 53 week period ending on the last Friday in September. The fiscal periods presented herein include the 13 week periods ended March 30, 2018 and March 31, 2017. Our fiscal year ending September 28, 2018 (fiscal 2018) and our fiscal year ended September 29, 2017 (fiscal 2017) both consist of 52 weeks.
Reclassifications	Reclassifications We have reclassified certain prior period amounts within our consolidated financial statements and accompanying notes to conform to our current period presentation. These reclassifications did not affect total revenue, operating income, or net income.

Summary Of Significant Accounting Policies (Policy)

6 Months Ended

Mar. 30, 2018

Principles of Consolidation

The unaudited interim condensed consolidated financial statements include the accounts of Dolby Laboratories, Inc. and our wholly owned subsidiaries. In addition, we have consolidated the financial results of jointly owned affiliated companies in which our principal stockholder has a controlling interest. We report these controlling interests as a separate line in our consolidated statements of operations as net income attributable to controlling interest and in our consolidated balance sheets as a controlling interest. We eliminate all intercompany accounts and transactions upon consolidation.

Operating Segments

Since we operate as a single reporting segment, all required financial segment information is included in our unaudited interim condensed consolidated financial statements. This determination reflects the fact that our CODM, our Chief Executive Officer, evaluates our financial information and resources, and assesses the performance of these resources on a consolidated basis.

Use of Estimates

The preparation of our financial statements in accordance with U.S. GAAP requires management to make certain estimates and assumptions that affect the amounts reported and disclosed in our unaudited interim condensed consolidated financial statements and accompanying notes. Significant items subject to such estimates and assumptions include estimated selling prices for elements sold in ME revenue arrangements; valuation allowances for accounts receivable; carrying values of inventories and certain property, plant, and equipment, goodwill and intangible assets; fair values of investments; accrued liabilities including liabilities for unrecognized tax benefits, deferred income tax assets and liabilities, and stock-based compensation. Actual results could differ from our estimates.

Fiscal Year

Our fiscal year is a 52 or 53 week period ending on the last Friday in September. The fiscal periods presented herein include the 13 week periods ended March 30, 2018 and March 31, 2017. Our fiscal year ending September 28, 2018 (fiscal 2018) and our fiscal year ended September 29, 2017 (fiscal 2017) both consist of 52 weeks.

Reclassifications

We have reclassified certain prior period amounts within our consolidated financial statements and accompanying notes to conform to our current period presentation. These reclassifications did not affect total revenue, operating income, or net income.