Stockholders' Equity (Schedule Of Controlling Interest) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended					6 Months Ended			12 Months Ended
	Mar. 30, 2012		Dec. 30, 2011		Apr. 01, 2011	Mar. 30, 2012		Apr. 01, 2011	Sep. 30, 2011
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance at September 30, 2011			$ 1,685,350			$ 1,685,350		$ 1,494,679	$ 1,494,679
Net income	88,317				82,482	161,683		169,247
Translation adjustments, net of taxes	1,934				2,237	1,557		3,344
Unrealized losses on available-for-sale securities, net of tax	306				220	192		(656)
Stock-based compensation expense						23,536		22,111
Repurchase of common stock	(60,081)	[1]	(26,068)	[1]		(86,149)	[1]	(75,124)
Tax benefit from the exercise of stock options and vesting of restricted stock units						(2,513)		11,320
Common stock issued under employee stock plans, net of shares withheld for taxes						3,524		15,215
Stockholders' Equity Attributable to Noncontrolling interest	1,787,167				1,640,136	1,787,167		1,640,136	1,685,350
Balance at March 30, 2012	1,787,167				1,640,136	1,787,167		1,640,136	1,685,350
Translation adjustment, tax						(373)			(301)
Unrealized losses on available-for-sale securities, tax						(109)			406
Dolby Laboratories, Inc. [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance at September 30, 2011			1,663,513			1,663,513		1,473,737	1,473,737
Net income						161,279		168,448
Translation adjustments, net of taxes						1,405		3,210
Unrealized losses on available-for-sale securities, net of tax						192		(656)
Stock-based compensation expense						23,536		22,111
Repurchase of common stock						(86,149)		(75,124)
Tax benefit from the exercise of stock options and vesting of restricted stock units						(2,513)		11,320
Common stock issued under employee stock plans, net of shares withheld for taxes						3,524		15,215
Stockholders' Equity Attributable to Noncontrolling interest	1,764,787				1,618,261	1,764,787		1,618,261
Balance at March 30, 2012	1,764,787				1,618,261	1,764,787		1,618,261
Controlling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance at September 30, 2011			21,837			21,837		20,942	20,942
Net income						404		799
Translation adjustments, net of taxes						152		134
Unrealized losses on available-for-sale securities, net of tax
Stock-based compensation expense
Repurchase of common stock
Tax benefit from the exercise of stock options and vesting of restricted stock units
Common stock issued under employee stock plans, net of shares withheld for taxes
Stockholders' Equity Attributable to Noncontrolling interest	22,380				21,875	22,380		21,875
Balance at March 30, 2012	$ 22,380				$ 21,875	$ 22,380		$ 21,875

[1] Cost of share repurchases includes the price paid per share and applicable commissions.