Stockholders' Equity And Stock-Based Compensation (Narrative) (Details) (USD $)	0 Months Ended		3 Months Ended		6 Months Ended		37 Months Ended	41 Months Ended
	Jan. 19, 2015	Oct. 21, 2014	Mar. 27, 2015	Mar. 28, 2014	Mar. 27, 2015	Mar. 28, 2014	Oct. 31, 2010	Mar. 28, 2014	Sep. 26, 2014
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options outstanding to purchase			9,233,000		9,233,000				7,611,000
Weighted average remaining contractual life					7 years 7 months 6 days
Year end stock price					$ 38.10
Percentage of vesting per year							50.00%
Common stock, dividends declared (in dollars per share)	$ 0.1	$ 0.1	$ 0.10	$ 0.00	$ 0.20	$ 0.00
Remaining authorization to purchase additional shares					$ 227,700,000
Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock options expected to vest			89,600,000		89,600,000
Employee stock options expected to be recognized over a weighted-average period					2 years 10 months 24 days
Employees and Officers [Member] | Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period					4 years
Awards Granted Prior to November 2010 [Member] | Directors [Member] | Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period							3 years	1 year
Awards Granted After November 2010 [Member] | Directors [Member] | Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period							2 years
Awards Granted Under 2005 Stock Plan Prior To February 2011 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Terms for issuance of stock					2
Awards Granted Under 2005 Stock Plan From February 2011 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Terms for issuance of stock					1.6
Employee Stock Purchase Plan [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Percentage of compensation withheld by employees to purchase common stock					10.00%
Common stock purchase price determined over percentage of closing price					15.00%
Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock options expected to vest			34,000,000		34,000,000
Employee stock options expected to be recognized over a weighted-average period					2 years 2 months 12 days
Class A Common Stock [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Common stock, shares authorized (shares)			500,000,000		500,000,000				500,000,000
Common stock, shares issued (shares)			51,383,446		51,383,446				50,658,627
Common stock, shares outstanding (shares)			51,383,446		51,383,446				50,658,627
Class A Common Stock [Member] | 2005 Stock Plan. [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares authorized under plan			38,000,000		38,000,000
Options outstanding to purchase			9,200,000		9,200,000
Weighted average remaining contractual life					7 years 6 months
Options vested and exercisable			4,200,000		4,200,000
Class A Common Stock [Member] | Employee Stock Purchase Plan [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Maximum value of common stock available for eligible employees					$ 25,000
Purchase period					6 months
Look back commencement period					1 year
Overlapping offering period					1 year
Class A Common Stock [Member] | Employee Stock Purchase Plan [Member] | Maximum [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Maximum number of common stock available for eligible employees					1,000
Class B Common Stock [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Common stock, shares authorized (shares)			500,000,000		500,000,000				500,000,000
Common stock, shares issued (shares)			51,073,661		51,073,661				51,610,239
Common stock, shares outstanding (shares)			51,073,661		51,073,661				51,610,239
Class B Common Stock [Member] | 2000 Stock Incentive Plan [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares authorized under plan			15,100,000		15,100,000
Options vesting period					4 years
Options expiration period					10 years
Options Granted Prior To June 2008 [Member] | Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options expiration period					10 years
Options Granted From June 2008 [Member] | Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period					4 years
Percentage of stock option becoming exercisable subjected to date of grant					25.00%