Interim Condensed Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Total Stockholders' Equity - Dolby Laboratories, Inc.	Controlling Interest	Class A Common Stock [Member] Common Stock	Class A Common Stock [Member] Additional Paid-In Capital
Beginning balance (in shares) at Sep. 27, 2019		99,000
Beginning balance at Sep. 27, 2019	$ 2,313,030		$ 0	$ 2,327,877	$ (20,625)	$ 2,307,351	$ 5,679
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	137,265			137,249		137,249	16
Other comprehensive income/(loss), net of tax	(11,184)				(10,990)	(10,990)	(194)
Distributions to controlling interest	(283)						283
Stock-based compensation expense	43,565		43,565			43,565
Shares repurchased (in shares)		(1,000)
Repurchase of common stock	(101,672)		(76,456)	(25,215)		(101,672)
Cash dividends declared and paid on common stock	(44,336)			(44,336)		(44,336)
Common stock issued under employee stock plans (in shares)								1,000
Common stock issued under employee stock plans	53,986		53,985			53,986
Tax withholdings on vesting of restricted stock (in shares)								0
Tax withholdings on vesting of restricted stock	(21,094)					(21,094)			$ (21,094)
Ending balance (in shares) at Mar. 27, 2020		99,000
Ending balance at Mar. 27, 2020	2,369,277		0	2,395,575	(31,615)	2,364,059	5,218
Beginning balance (in shares) at Dec. 27, 2019		99,000
Beginning balance at Dec. 27, 2019	2,338,701		0	2,351,251	(18,060)	2,333,290	5,411
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	88,674			88,496		88,496	178
Other comprehensive income/(loss), net of tax	(13,926)				(13,555)	(13,555)	(371)
Stock-based compensation expense	20,951		20,951			20,951
Shares repurchased (in shares)		(1,000)
Repurchase of common stock	(71,669)		(49,751)	(21,917)		(71,669)
Cash dividends declared and paid on common stock	(22,255)			(22,255)		(22,255)
Common stock issued under employee stock plans (in shares)								1,000
Common stock issued under employee stock plans	29,613		29,612			29,613
Tax withholdings on vesting of restricted stock (in shares)								0
Tax withholdings on vesting of restricted stock	(812)					(812)	0		(812)
Ending balance (in shares) at Mar. 27, 2020		99,000
Ending balance at Mar. 27, 2020	2,369,277		0	2,395,575	(31,615)	2,364,059	5,218
Beginning balance (in shares) at Sep. 25, 2020		99,000
Beginning balance at Sep. 25, 2020	2,438,405		0	2,443,138	(10,594)	2,432,643	5,762
Ending balance (in shares) at Dec. 25, 2020		100,000
Ending balance at Dec. 25, 2020	2,571,217		0	2,565,670	(608)	2,565,162	6,055
Beginning balance (in shares) at Sep. 25, 2020		99,000
Beginning balance at Sep. 25, 2020	2,438,405		0	2,443,138	(10,594)	2,432,643	5,762
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	219,035			211,415		211,415	7,620
Other comprehensive income/(loss), net of tax	6,824				6,555	6,555	269
Distributions to controlling interest	(7,362)						(7,362)
Stock-based compensation expense	$ 50,726		50,726			50,726
Shares repurchased (in shares)	(1,207,418)	(1,000)
Repurchase of common stock	$ (110,775)		(92,665)	(18,109)		(110,775)
Cash dividends declared and paid on common stock	(44,574)			(44,574)		(44,574)
Common stock issued under employee stock plans	71,157	$ 2	71,155			71,157
Tax withholdings on vesting of restricted stock	(29,216)					(29,216)			(29,216)
Ending balance (in shares) at Mar. 26, 2021		100,000
Ending balance at Mar. 26, 2021	2,594,220		0	2,591,870	(4,039)	2,587,931	6,289
Beginning balance (in shares) at Dec. 25, 2020		100,000
Beginning balance at Dec. 25, 2020	2,571,217		0	2,565,670	(608)	2,565,162	6,055
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	76,345			76,217		76,217	128
Other comprehensive income/(loss), net of tax	(3,325)				(3,431)	(3,431)	106
Stock-based compensation expense	24,413		24,413			24,413
Shares repurchased (in shares)		(1,000)
Repurchase of common stock	(70,790)		(43,115)	(27,674)		(70,790)
Cash dividends declared and paid on common stock	(22,343)			(22,343)		(22,343)
Common stock issued under employee stock plans	19,834	$ 0	19,834			19,834
Tax withholdings on vesting of restricted stock (in shares)								1,000
Tax withholdings on vesting of restricted stock	(1,131)				0	(1,131)	0		$ (1,132)
Ending balance (in shares) at Mar. 26, 2021		100,000
Ending balance at Mar. 26, 2021	$ 2,594,220		$ 0	$ 2,591,870	$ (4,039)	$ 2,587,931	$ 6,289