Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands	Total	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Total Dolby Laboratories,Inc.[Member]	Controlling Interest [Member]	Class B Common Stock [Member] Common Stock [Member]	Common Class A [Member] Common Stock [Member]
Beginning balance, shares at Sep. 25, 2015							50,743,000	50,292,000
Beginning balance, value at Sep. 25, 2015	$ 1,816,007	$ 17,571	$ 1,800,857	$ (11,462)	$ 1,807,068	$ 8,939	$ 51	$ 51
Net income	186,402		185,860		185,860	542
Translation adjustments, net of taxes	85			873	873	(788)
Unrealized gains/(losses) on available-for-sale securities, net of tax	392			392	392
Distributions to controlling interest	(214)					(214)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	66,985	66,985			66,985
Repurchase of common stock, shares								(2,616,000)
Repurchase of common stock, value	(100,854)	(100,851)			(100,854)			$ (3)
Cash dividends declared and paid on common stock	(48,397)		(48,397)		(48,397)
Tax benefit/(deficiency) from the stock incentive plans	850	850			850
Class A common stock issued under employee stock plans, shares								3,382,000
Class A common stock issued under employee stock plans, value	71,111	71,108			71,111			$ 3
Shares repurchased for tax witholdings on vesting of restricted stock, shares								(379,000)
Shares repurchased for tax witholdings on vesting of restricted stock, value	(13,632)	(13,631)			(13,632)			$ (1)
Transfer of Class B common stock to Class A common stock, shares							6,339,000	(6,339,000)
Transfer of Class B common stock to Class A common stock, value							$ 7	$ (7)
Ending balance, shares at Sep. 30, 2016							44,404,000	57,018,000
Ending balance, value at Sep. 30, 2016	1,978,735	42,032	1,938,320	(10,197)	1,970,256	8,479	$ 44	$ 57
Net income	202,427		201,802		201,802	625
Translation adjustments, net of taxes	3,653			3,563	3,563	90
Unrealized gains/(losses) on available-for-sale securities, net of tax	(1,119)			(1,119)	(1,119)
Distributions to controlling interest	(2,094)					(2,094)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	65,343	65,343			65,343
Repurchase of common stock, shares								(2,025,000)
Repurchase of common stock, value	(100,000)	(99,998)			(100,000)			$ (2)
Cash dividends declared and paid on common stock	(57,059)		(57,059)		(57,059)
Tax benefit/(deficiency) from the stock incentive plans	1,634	1,634			1,634
Class A common stock issued under employee stock plans, shares								3,138,000
Class A common stock issued under employee stock plans, value	69,998	69,996			69,998			$ 2
Shares repurchased for tax witholdings on vesting of restricted stock, shares								(379,000)
Shares repurchased for tax witholdings on vesting of restricted stock, value	(17,676)	(17,676)			(17,676)
Transfer of Class B common stock to Class A common stock, shares							1,530,000	(1,530,000)
Transfer of Class B common stock to Class A common stock, value							$ 1	$ (1)
Ending balance, shares at Sep. 29, 2017							42,874,000	59,282,000
Ending balance, value at Sep. 29, 2017	2,143,842	61,331	2,083,063	(7,753)	2,136,742	7,100	$ 43	$ 58
Net income	122,805		122,246		122,246	559
Translation adjustments, net of taxes	(5,578)			(5,508)	(5,508)	(70)
Unrealized gains/(losses) on available-for-sale securities, net of tax	(2,571)			(2,571)	(2,571)
Distributions to controlling interest	(1,022)					1,022
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	$ 71,249	71,249			71,249
Repurchase of common stock, shares	(2,381,100)							(2,381,000)
Repurchase of common stock, value	$ (150,470)	150,468			150,470			$ 2
Cash dividends declared and paid on common stock	(66,155)		(66,155)		(66,155)
Class A common stock issued under employee stock plans, shares								3,823,000
Class A common stock issued under employee stock plans, value	106,162	106,159			106,162			$ 3
Shares repurchased for tax witholdings on vesting of restricted stock, shares								(358,000)
Shares repurchased for tax witholdings on vesting of restricted stock, value	(22,144)	(22,144)			(22,144)			$ 0
Transfer of Class B common stock to Class A common stock, shares							3,613,000	(3,613,000)
Transfer of Class B common stock to Class A common stock, value							$ 2	$ (2)
Ending balance, shares at Sep. 28, 2018							39,261,000	63,979,000
Ending balance, value at Sep. 28, 2018	$ 2,196,118	$ 66,127	$ 2,139,154	$ (15,832)	$ 2,189,551	$ 6,567	$ 41	$ 61