Derivative Instruments and Hedging Activities (Pretax Amounts Recognized In Accumulated Other Comprehensive Income On Currency Contracts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the year	$ 405,260	$ 258,142
Balance at the end of the year	428,777	405,260
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the year	673	1,005
Balance at the end of the year	3,946	673
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Foreign Exchange Cash Flow Hedges [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the year	(400)	608
Net (gain) loss reclassified into revenue (effective portion)	(459)	334
Net gain (loss) recognized in OCI (effective portion)	416	(1,342)
Balance at the end of the year	(443)	(400)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the year	(255)	386
Balance at the end of the year	1,953	(255)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Swap [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the year	0	0
Net (gain) loss reclassified into revenue (effective portion)	614	0
Net gain (loss) recognized in OCI (effective portion)	2,885	0
Balance at the end of the year	$ 3,499	$ 0