Interim Condensed Consolidated Statements Of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Related party rent expense:
Included in operating expenses	$ (5)	$ (36)	$ (392)	$ 112
Included in net income attributable to controlling interest	$ 71	$ 116	$ 311	$ 337

Costs and Expenses, Related Party Attributable to Controlling Interest

No definition available.

Name:	dlb_CostsAndExpensesRelatedPartyAttributableToControllingInterest
Namespace Prefix:	dlb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration