Interim Condensed Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Total Dolby Laboratories,Inc.[Member]	Controlling Interest [Member]
Beginning balance at Sep. 27, 2013	$ 1,500,026	$ 102	$ 18,812	$ 1,454,382	$ 7,814	$ 1,481,110	$ 18,916
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	121,795			120,383		120,383	1,412
Translation adjustments, net of tax of $829 and $(64), respectively	921				703	703	218
Unrealized gains (losses) on available-for-sale securities, net of tax of $(327) and $(98), respectively	(177)				(177)	(177)
Stock-based compensation expense	32,807		32,807			32,807
Repurchase of common stock	(11,660)		(11,660)			(11,660)
Tax benefit/(deficiency) from the stock incentive plans	10		10			10
Common stock issued under employee stock plans	17,309	1	17,308			17,309
Tax withholdings on vesting of restricted stock	(8,358)		(8,358)			(8,358)
Exercise of class B stock options	155		155			155
Ending balance at Mar. 28, 2014	1,653,182	103	49,074	1,574,765	8,694	1,632,636	20,546
Beginning balance at Sep. 26, 2014	1,731,648	103	46,415	1,660,485	3,014	1,710,017	21,631
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	100,469			99,331		99,331	1,138
Translation adjustments, net of tax of $829 and $(64), respectively	(11,872)				(11,211)	(11,211)	(661)
Unrealized gains (losses) on available-for-sale securities, net of tax of $(327) and $(98), respectively	(665)				(665)	(665)
Distributions to controlling interest	(5,628)			0		0	(5,628)
Stock-based compensation expense	34,509		34,509			34,509
Repurchase of common stock	(32,364)	(1)	(32,363)			(32,364)
Cash dividends declared and paid on common stock	(20,470)			(20,470)		(20,470)
Tax benefit/(deficiency) from the stock incentive plans	(1,273)		(1,273)			(1,273)
Common stock issued under employee stock plans	12,631	1	12,630			12,631
Tax withholdings on vesting of restricted stock	(11,809)		(11,809)			(11,809)
Exercise of class B stock options	7		7			7
Ending balance at Mar. 27, 2015	$ 1,799,059	$ 103	$ 50,662	$ 1,739,346	$ (7,532)	$ 1,782,579	$ 16,480