Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	$ (18,060)	$ (18,639)	$ (20,625)	$ (15,832)
Unrealized Gains (Losses)	(3,943)		(5,837)
Income Tax Effect - Benefit/(Expense)	67	99	70	99
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(13,656)	3,836	(12,144)	1,190
Realized (Gains) - Investment Securities	117	135	1,431	(66)
Income Tax Effect - (Benefit)/Expense	(16)	(15)	(277)	25
Net Of Tax	101	120	1,154	(41)
Net current-period other comprehensive income/(loss)	(13,555)	3,956	(10,990)	1,149
Balance, End Of Period	(31,615)	(14,683)	(31,615)	(14,683)
Unrealized Gains/Losses On Available-For-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	1,036	(2,178)	2,198	(2,948)
Unrealized Gains (Losses)	135	1,879	(2,074)	2,810
Income Tax Effect - Benefit/(Expense)	70	99	70	99
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	205	1,978	(2,004)	2,909
Realized (Gains) - Investment Securities	84	135	1,392	(66)
Income Tax Effect - (Benefit)/Expense	(16)	(15)	(277)	25
Net Of Tax	68	120	1,115	(41)
Net current-period other comprehensive income/(loss)	273	2,098	(889)	2,868
Balance, End Of Period	1,309	(80)	1,309	(80)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	284		0	0
Unrealized Gains (Losses)	(4,078)		(3,763)
Income Tax Effect - Benefit/(Expense)	37		0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4,041)		(3,763)
Realized (Gains) - Investment Securities	33		39
Net Of Tax	33		39
Net current-period other comprehensive income/(loss)	(4,008)		(3,724)
Balance, End Of Period	(3,724)		(3,724)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	(19,380)	(16,461)	(22,823)	(12,884)
Unrealized Gains (Losses)	(9,780)	1,858	(6,377)	(1,719)
Income Tax Effect - Benefit/(Expense)	(40)	0	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(9,820)	1,858	(6,377)	(1,719)
Net current-period other comprehensive income/(loss)	(9,820)	1,858	(6,377)	(1,719)
Balance, End Of Period	$ (29,200)	$ (14,603)	$ (29,200)	$ (14,603)