Stockholders' Equity And Stock-Based Compensation (Summary Of Stock Options Issued To Officers, Directors, And Employees Under 2000 Stock Incentive Plan And 2005 Stock Plan) (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Mar. 29, 2024 USD ($) $ / shares shares
Shares
Shares, Options outstanding at beginning of period (in shares) | shares	3,720,000
Shares, Grants (in shares) | shares	271,000
Shares, Exercises (in shares) | shares	(408,000)
Shares, Forfeitures and cancellations (in shares) | shares	(49,000)
Shares, Options vested and expected to vest (in shares) | shares	3,388,000
Weighted-Average Exercise Price
Weighted Average Exercise Price, Options outstanding at beginning of period (in usd per share) | $ / shares	$ 66.13
Weighted Average Exercise Price, Grants (in usd per share) | $ / shares	87.49
Weighted Average Exercise Price, Exercises (in usd per share) | $ / shares	53.02
Weighted Average Exercise Price, Forfeitures and cancellations (in usd per share) | $ / shares	89.66
Weighted Average Exercise Price, Options outstanding at end of period (in usd per share) | $ / shares	69.01
Weighted Average Exercise Price, Options vested and expected to vest (in usd per share) | $ / shares	68.72
Weighted Average Exercise Price, Options exercisable (in usd per share) | $ / shares	$ 65.60
Weighted Average Remaining Contractual Life, Options vested and expected to vest at end of period	5 years 3 months
Weighted Average Remaining Contractual Life, Options exercisable	4 years 5 months 19 days
Aggregate Intrinsic Value, Options outstanding | $	$ 56,345
Aggregate Intrinsic Value, Options vested and expected to vest | $	56,100
Aggregate Intrinsic Value, Options exercisable | $	$ 53,313
Year End Stock Price (in dollars per share) | $ / shares	$ 83.77
2005 Stock Plan. [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vested and exercisable (in shares) | shares	2,767,000
Weighted average remaining contractual life	5 years 3 months 29 days
Shares
Shares, Options outstanding at end of period (in shares) | shares	3,534,000
Weighted-Average Exercise Price
Weighted Average Remaining Contractual Life, Options outstanding	5 years 3 months 29 days
Performance-Based Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares exercisable (in shares) | shares	228,108