Shareholders' Equity And Earnings Per Share (Components Of Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 4,492,256	$ 4,252,511	$ 4,498,688	$ 4,115,995
Other comprehensive (loss) income during the period, net of tax, before reclassifications	(127,748)	(4,546)	(251,551)	(14,540)
Amount reclassified from accumulated other comprehensive (loss) income into net income, net of tax	742	4,609	4,485	9,367
Amount reclassified from accumulated other comprehensive (loss) income related to amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale, net of tax	(32)	(34)	(63)	(76)
Total other comprehensive (loss) income	(127,038)	29	(247,129)	(5,249)
Ending balance	4,727,623	4,339,011	4,727,623	4,339,011
Accumulated Unrealized Gains (Losses) on Securities
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(142,604)	26,022	8,724	70,737
Other comprehensive (loss) income during the period, net of tax, before reclassifications	(122,154)	4,628	(273,268)	(39,891)
Amount reclassified from accumulated other comprehensive (loss) income into net income, net of tax	0	(427)	(183)	(581)
Amount reclassified from accumulated other comprehensive (loss) income related to amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale, net of tax	(32)	(34)	(63)	(76)
Total other comprehensive (loss) income	(122,186)	4,167	(273,514)	(40,548)
Ending balance	(264,790)	30,189	(264,790)	30,189
Accumulated Unrealized Gains (Losses) on Derivative Instruments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	56,060	14,167	27,111	(23,090)
Other comprehensive (loss) income during the period, net of tax, before reclassifications	999	(11,483)	26,022	20,862
Amount reclassified from accumulated other comprehensive (loss) income into net income, net of tax	742	5,036	4,668	9,948
Amount reclassified from accumulated other comprehensive (loss) income related to amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale, net of tax	0	0	0	0
Total other comprehensive (loss) income	1,741	(6,447)	30,690	30,810
Ending balance	57,801	7,720	57,801	7,720
Accumulated Foreign Currency Translation Adjustments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(29,455)	(30,085)	(31,743)	(32,265)
Other comprehensive (loss) income during the period, net of tax, before reclassifications	(6,593)	2,309	(4,305)	4,489
Amount reclassified from accumulated other comprehensive (loss) income into net income, net of tax	0	0	0	0
Amount reclassified from accumulated other comprehensive (loss) income related to amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale, net of tax	0	0	0	0
Total other comprehensive (loss) income	(6,593)	2,309	(4,305)	4,489
Ending balance	(36,048)	(27,776)	(36,048)	(27,776)
Accumulated other comprehensive income (loss)
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(115,999)	10,104	4,092	15,382
Total other comprehensive (loss) income	(127,038)	29	(247,129)	(5,249)
Ending balance	$ (243,037)	$ 10,133	$ (243,037)	$ 10,133