Fair Value (Schedule Of Financial Instruments Measured At Fair Value On Recurring Basis) (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 30, 2012	Sep. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	$ 221,611
Auction rate securities	3,093	2,288
Total	224,704
Contingent consideration liability recorded for business combinations	59,400
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	221,611
Auction rate securities	0
Total	221,611
Contingent consideration liability recorded for business combinations	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	0
Auction rate securities	0
Total	0
Contingent consideration liability recorded for business combinations	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	0
Auction rate securities	3,093
Total	3,093
Contingent consideration liability recorded for business combinations	$ 59,400	$ 59,400