Summary Of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 25, 2020	Sep. 24, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 63,141		$ 67,128
Total lease liabilities	67,927
Revenues	351,633	$ 389,874
Gross margin	318,924	354,570
Provision for income taxes	(11,432)	(24,272)
Net income (loss) attributable to Dolby Laboratories, Inc.	$ 80,014	$ 135,198
Diluted (in usd per share)	$ 0.77	$ 1.30
Accounts receivable, net	$ 241,449		232,609
Contract assets, net of allowance for credit losses of $144 and $208	226,809		182,316
Prepaid expenses and other current assets	68,693		62,737
Other non-current assets	61,331		61,257
Accrued liabilities	225,847		262,728
Contract liabilities	21,426		18,473
Non-current contract liabilities	24,117		23,713
Other non-current liabilities	102,378		105,310
Retained earnings	2,649,175		$ 2,607,909
Net income	80,010	$ 142,690
Deferred income taxes	(9,004)	(15,439)
Accounts receivable, net	(9,965)	(111,902)
Contract assets	(44,428)	(26,384)
Prepaid expenses and other assets	(7,082)	6,397
Accounts payable and other liabilities	(34,034)	30,397
Contract liabilities	3,350	5,153
Net cash provided by operating activities	$ 31,660	$ 82,160