Shareholders' Equity And Earnings Per Share (Components Of Other Comprehensive Income or Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 4,727,623	$ 4,339,011	$ 4,498,688	$ 4,115,995
Other comprehensive loss during the period, net of tax, before reclassifications	(211,652)	(13,393)	(463,203)	(27,933)
Amount reclassified from accumulated other comprehensive income or loss into net income, net of tax	(4,007)	4,717	478	14,084
Amount reclassified from accumulated other comprehensive income or loss related to amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale, net of tax	(32)	(40)	(95)	(116)
Total other comprehensive loss	(215,691)	(8,716)	(462,820)	(13,965)
Ending balance	4,637,980	4,410,317	4,637,980	4,410,317
Accumulated Unrealized (Losses) Gains on Securities
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(264,790)	30,189	8,724	70,737
Other comprehensive loss during the period, net of tax, before reclassifications	(141,758)	(10,374)	(415,026)	(50,265)
Amount reclassified from accumulated other comprehensive income or loss into net income, net of tax	(9)	(256)	(192)	(837)
Amount reclassified from accumulated other comprehensive income or loss related to amortization of unrealized gains on investment securities transferred to held-to-maturity from available-for-sale, net of tax	(32)	(40)	(95)	(116)
Total other comprehensive loss	(141,799)	(10,670)	(415,313)	(51,218)
Ending balance	(406,589)	19,519	(406,589)	19,519
Accumulated Unrealized Gains (Losses) on Derivative Instruments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	57,801	7,720	27,111	(23,090)
Other comprehensive loss during the period, net of tax, before reclassifications	(52,072)	1,631	(26,050)	22,493
Amount reclassified from accumulated other comprehensive income or loss into net income, net of tax	(3,998)	4,973	670	14,921
Amount reclassified from accumulated other comprehensive income or loss 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	(56,070)	6,604	(25,380)	37,414
Ending balance	1,731	14,324	1,731	14,324
Accumulated Foreign Currency Translation Adjustments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(36,048)	(27,776)	(31,743)	(32,265)
Other comprehensive loss during the period, net of tax, before reclassifications	(17,822)	(4,650)	(22,127)	(161)
Amount reclassified from accumulated other comprehensive income or loss into net income, net of tax	0	0	0	0
Amount reclassified from accumulated other comprehensive income or loss 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	(17,822)	(4,650)	(22,127)	(161)
Ending balance	(53,870)	(32,426)	(53,870)	(32,426)
Accumulated other comprehensive income (loss)
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(243,037)	10,133	4,092	15,382
Total other comprehensive loss	(215,691)	(8,716)	(462,820)	(13,965)
Ending balance	$ (458,728)	$ 1,417	$ (458,728)	$ 1,417