Stockholders' Equity And Stock-Based Compensation (Narrative) (Details) - USD ($)							3 Months Ended	12 Months Ended				37 Months Ended	41 Months Ended
	Jul. 20, 2015	Apr. 20, 2015	Jan. 19, 2015	Oct. 21, 2014	Dec. 21, 2012	Dec. 11, 2012	Sep. 25, 2015	Sep. 25, 2015	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012	Oct. 31, 2010	Mar. 28, 2014	Oct. 31, 2014	Feb. 29, 2012	Jul. 31, 2011	Jul. 31, 2010	Nov. 30, 2009
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options granted under the plan								2,573,000
Options outstanding to purchase									7,611,000
Recognized tax benefit from the exercise of ISO and ESPP								$ 328,000	$ 538,000	$ 417,000
Percentage of vesting per year												50.00%
Share based compensation expense								67,069,000	65,680,000	64,328,000
Fair value of restricted stock units vested								$ 45,175,000	40,810,000	27,013,000
Year end stock price								$ 31.40
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period								1,322,000
Employee stock options expected to be recognized over a weighted-average period								7 years 1 month 6 days
Accrued liabilities included in employee withholdings.							$ 169,307,000	$ 169,307,000	158,376,000
Allocated Share-based Compensation Expense								67,069,000	$ 65,680,000	$ 64,328,000
Stock authorized for repurchase							1,100,000,000	1,100,000,000										$ 250,000,000
Remaining authorization to purchase additional shares							$ 152,700,000	$ 152,700,000
Common stock, dividends declared (in dollars per share)	$ 0.1	$ 0.1	$ 0.1	$ 0.1			$ 0.12	$ 0.42	$ 0.00	$ 4.00
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)							50,291,426	50,291,426	50,658,627
Common stock, shares outstanding (shares)							50,291,426	50,291,426	50,658,627
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)							50,743,311	50,743,311	51,610,239
Common stock, shares outstanding (shares)							50,743,311	50,743,311	51,610,239
2000 Stock Incentive Plan. [Member] | Class B Common Stock [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 maximum vesting period, months								4 years
2005 Stock Plan. [Member] | Class A Common Stock [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares authorized under plan							29,000,000	29,000,000
Options outstanding to purchase							8,835,000	8,835,000
Weighted Average Remaining Contractual Life, Options outstanding								7 years 2 months 12 days
Options vested and exercisable							4,527,000	4,527,000
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
Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share based compensation expense								$ 40,332,000	$ 42,221,000	$ 39,644,000
Employee Stock Purchase Plan [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share based compensation expense								$ 3,765,000	3,779,000	$ 3,350,000
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 Purchase Plan [Member] | Class A Common Stock [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Maximum value of common stock available for eligible employees								$ 25,000
Maximum number of common stock available for eligible employees								1,000
Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock options expected to vest							$ 38,500,000	$ 38,500,000
Employee stock options expected to be recognized over a weighted-average period								2 years 4 months 24 days
Employee Stock Option [Member] | Options Granted Prior To June 2008 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options expiration period										10 years
Expiration period after termination of service, months										3 months
Employee Stock Option [Member] | Options Granted From June 2008 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period										4 years	36 months
Options expiration period										10 years
Expiration period after termination of service, months										3 months
Percentage of stock option becoming exercisable subjected to date of grant										25.00%
Options maximum vesting period, months										4 years	36 months
Additional Stock Approved [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock authorized for repurchase														$ 200,000,000	$ 100,000,000	$ 250,000,000	$ 300,000,000
Equity Award Modification [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Common stock, shares outstanding (shares)					102,051,386
Common stock, dividends declared (in dollars per share)						$ 4.00
Dividends, amount					$ 408,200,000
Share-based Compensation Expense, Total Incremental Charge						$ 7,900,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Compensation Expense, Total Incremental Charge								$ 1,100,000	1,200,000	$ 4,600,000
Equity Award Modification Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Expense, Total Incremental Charge					$ 11,900,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Compensation Expense, Total Incremental Charge								2,400,000	$ 3,000,000	$ 4,300,000
Minimum [Member] | Equity Award Modification [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period										1 year
Options maximum vesting period, months										1 year
Minimum [Member] | Equity Award Modification Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period										1 year
Options maximum vesting period, months										1 year
Maximum [Member] | Equity Award Modification [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period										4 years
Options maximum vesting period, months										4 years
Maximum [Member] | Equity Award Modification Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period										4 years
Options maximum vesting period, months										4 years
Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock options expected to vest							$ 73,900,000	$ 73,900,000
Employee stock options expected to be recognized over a weighted-average period								2 years 7 months 6 days
Employee and Officer [Member] | Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period									4 years
Options maximum vesting period, months									4 years
Awards Granted Prior to November 2010 [Member] | Director [Member] | Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period												3 years	1 year
Options maximum vesting period, months												3 years	1 year
Awards Granted After November 2010 [Member] | Director [Member] | Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options vesting period												2 years
Options maximum vesting period, months												2 years