Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 26, 2021	Mar. 27, 2020	Mar. 26, 2021	Mar. 27, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	$ (608)	$ (18,060)	$ (10,594)	$ (20,625)
Unrealized Gains (Losses)	(5,397)	(3,943)	(4,517)	(5,837)
Income Tax Effect - Benefit/(Expense)	133	67	(386)	70
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(6,101)	(13,656)	2,737	(12,144)
Realized (Gains) - Investment Securities	2,834	117	4,223	1,431
Income Tax Effect - (Benefit)/Expense	(164)	(16)	(405)	(277)
Net Of Tax	2,670	101	3,818	1,154
Net current-period other comprehensive income/(loss)	(3,431)	(13,555)	6,555	(10,990)
Balance, End Of Period	(4,039)	(31,615)	(4,039)	(31,615)
Unrealized Gains/Losses On Available-For-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	653	1,036	818	2,198
Unrealized Gains (Losses)	(423)	135	(607)	(2,074)
Income Tax Effect - Benefit/(Expense)	52	70	56	70
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(371)	205	(551)	(2,004)
Realized (Gains) - Investment Securities	184	84	201	1,392
Income Tax Effect - (Benefit)/Expense	(8)	(16)	(10)	(277)
Net Of Tax	176	68	191	1,115
Net current-period other comprehensive income/(loss)	(195)	273	(360)	(889)
Balance, End Of Period	458	1,309	458	1,309
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	6,115	284	3,969	0
Unrealized Gains (Losses)	(4,974)	(4,078)	(3,910)	(3,763)
Income Tax Effect - Benefit/(Expense)	116	37	65	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4,858)	(4,041)	(3,845)	(3,763)
Realized (Gains) - Investment Securities	2,650	33	4,022	39
Income Tax Effect - (Benefit)/Expense	(156)	0	(395)
Net Of Tax	2,494	33	3,627	39
Net current-period other comprehensive income/(loss)	(2,364)	(4,008)	(218)	(3,724)
Balance, End Of Period	3,751	(3,724)	3,751	(3,724)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, Beginning Of Period	(7,376)	(19,380)	(15,381)	(22,823)
Unrealized Gains (Losses)	(837)	(9,780)	7,640	(6,377)
Income Tax Effect - Benefit/(Expense)	(35)	(40)	(507)	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(872)	(9,820)	7,133	(6,377)
Net current-period other comprehensive income/(loss)	(872)	(9,820)	7,133	(6,377)
Balance, End Of Period	$ (8,248)	$ (29,200)	$ (8,248)	$ (29,200)