Stockholders' Equity And Stock-Based Compensation (Narrative) (Details)										3 Months Ended		6 Months Ended		41 Months Ended
	May 05, 2022 $ / shares	Feb. 03, 2022 USD ($) $ / shares	Dec. 15, 2021 shares	Dec. 15, 2020 shares	Dec. 16, 2019 shares	Dec. 15, 2018 shares	Dec. 15, 2017 shares	Dec. 15, 2016 shares	Dec. 15, 2015 shares	Apr. 01, 2022 USD ($) vote $ / shares shares	Mar. 26, 2021 $ / shares	Apr. 01, 2022 USD ($) vote $ / shares shares	Mar. 26, 2021 $ / shares	Mar. 28, 2014	Sep. 24, 2021 shares	Jul. 29, 2021 USD ($)	Jul. 31, 2019 USD ($)	Jul. 25, 2018 USD ($)	Jan. 25, 2017 USD ($)	Oct. 31, 2014 USD ($)	Feb. 29, 2012 USD ($)	Jul. 31, 2011 USD ($)	Jul. 31, 2010 USD ($)	Nov. 30, 2009 USD ($)
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options outstanding to purchase															4,577,000
Year end stock price (in dollars per share) | $ / shares												$ 79.09
Cash dividend declared per common share (in dollars per share) | $ / shares		$ 0.25								$ 0.25	$ 0.22	$ 0.50	$ 0.44
Remaining authorization to purchase additional shares | $										$ 420,900,000		$ 420,900,000
Authorization Amount | $										2,600,000,000		2,600,000,000												$ 250,000,000
Subsequent Event
Stockholders' Equity And Stock-Based Compensation [Line Items]
Cash dividend declared per common share (in dollars per share) | $ / shares	$ 0.25
Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock options expected to vest | $										$ 16,400,000		$ 16,400,000
Employee stock options expected to be recognized over a weighted-average period												2 years 4 months 24 days
Performance-Based Stock Options [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares exercisable (in shares)										437,749		437,749
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												7 years
Compensation requisite measurement period												3 years
Performance-Based Stock Options [Member] | Executive Officer [Member] | Awarded Fiscal 2018 [Member] [Domain]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares exercisable (in shares)							253,440
Percentage Of Target Award							96.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures							264,000
Performance-Based Stock Options [Member] | Executive Officer [Member] | Awarded Fiscal 2016 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Percentage Of Target Award									125.00%
Options vested and exercisable (in shares)									334,623
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures									419,623
Performance-Based Stock Options [Member] | Executive Officer [Member] | Awarded Fiscal 2017 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares exercisable (in shares)								240,539
Percentage Of Target Award								95.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures								276,199
Performance-Based Stock Options [Member] | Executive Officer [Member] | Awarded Fiscal 2019 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares exercisable (in shares)						158,700
Percentage Of Target Award						75.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures						241,100
Performance-Based Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Compensation requisite measurement period												3 years
Performance-Based Restricted Stock Units [Member] | Executive Officer [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares exercisable (in shares)			120,602	132,276	124,000
Percentage Of Target Award			200.00%	200.00%	200.00%							200.00%
Options outstanding to purchase			60,301	66,138	62,000					162,846		162,846
Performance-Based Restricted Stock Units [Member] | Vesting Shares At 200% Of The Target Award Amount | Executive Officer [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options outstanding to purchase										325,692		325,692
Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												4 years
Stock options expected to vest | $										$ 230,300,000		$ 230,300,000
Employee stock options expected to be recognized over a weighted-average period												2 years 9 months 18 days
Restricted Stock Units (RSUs) [Member] | Employees and Officers [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												4 years
Restricted Stock Units (RSUs) [Member] | Awards Granted Prior to November 2010 [Member] | Directors [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period														1 year
Awards Granted Under 2005 Stock Plan Prior To February 2011 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Terms for issuance of stock (in shares)												2
Awards Granted Under 2005 Stock Plan From February 2011 [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Terms for issuance of stock (in shares)												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%
Discount from market price on purchase date												15.00%
Additional Stock Approved [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Authorization Amount | $		$ 250,000,000														$ 350,000,000	$ 350,000,000	$ 350,000,000	$ 200,000,000	$ 200,000,000	$ 100,000,000	$ 250,000,000	$ 300,000,000
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)										64,789,579		64,789,579			64,986,316
Common stock, number of votes per share | vote										1		1
Common stock, shares outstanding (shares)										64,789,579		64,789,579			64,986,316
Class A Common Stock [Member] | 2005 Stock Plan. [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Shares authorized under plan										55,000,000		55,000,000
Options outstanding to purchase										4,253,000		4,253,000
Weighted average remaining contractual life												5 years 9 months 14 days
Options vested and exercisable (in shares)										3,072,000		3,072,000
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
Maximum number of common stock available for eligible employees (in shares)												1,000
Purchase period												6 months
Look back commencement period												1 year
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)										36,086,629		36,086,629			36,086,779
Common stock, number of votes per share | vote										10		10
Common stock, shares outstanding (shares)										36,086,629		36,086,629			36,086,779
Options Granted From June Two Thousand Eight Member | Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												4 years
Options Granted From June Two Thousand Eight Member | Employee Stock Option [Member] | One year anniversary date
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												1 year
Percentage of stock option becoming exercisable subjected to date of grant												25.00%
Options Granted From June Two Thousand Eight Member | Employee Stock Option [Member] | Over 36 equally installment periods following one year anniversary date
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												36 months
Awards Granted After November 2010 Member [Member] | Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period												1 year
Minimum [Member] | Performance-Based Stock Options [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Percentage Of Target Award												0.00%
Minimum [Member] | Performance-Based Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Percentage Of Target Award												0.00%
Minimum [Member] | Options Granted From June Two Thousand Eight Member | Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options expiration period												3 months
Maximum [Member] | Performance-Based Stock Options [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Percentage Of Target Award												125.00%
Maximum [Member] | Performance-Based Restricted Stock Units [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Percentage Of Target Award												200.00%
Maximum [Member] | Options Granted From June Two Thousand Eight Member | Employee Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Options expiration period												10 years