Accumulated Other Comprehensive Income or Loss and Earnings Per Share (Components Of Other Comprehensive Income or Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 4,796,838	$ 4,498,688
Other comprehensive income during the period, net of tax, before reclassifications	58,021	(123,803)
Amount reclassified from accumulated other comprehensive loss into net income, net of tax	2,211	3,743
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)	(31)
Total other comprehensive income (loss)	60,200	(120,091)
Ending balance	5,015,506	4,492,256
Accumulated Unrealized (Losses) Gains on Securities
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(386,057)	8,724
Other comprehensive income during the period, net of tax, before reclassifications	34,503	(151,114)
Amount reclassified from accumulated other comprehensive loss into net income, net of tax	(409)	(183)
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)	(31)
Total other comprehensive income (loss)	34,062	(151,328)
Ending balance	(351,995)	(142,604)
Accumulated Unrealized Gains (Losses) on Derivative Instruments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	7,381	27,111
Other comprehensive income during the period, net of tax, before reclassifications	22,808	25,023
Amount reclassified from accumulated other comprehensive loss into net income, net of tax	2,620	3,926
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
Total other comprehensive income (loss)	25,428	28,949
Ending balance	32,809	56,060
Accumulated Foreign Currency Translation Adjustments
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(48,960)	(31,743)
Other comprehensive income during the period, net of tax, before reclassifications	710	2,288
Amount reclassified from accumulated other comprehensive loss into net income, net of tax	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
Total other comprehensive income (loss)	710	2,288
Ending balance	(48,250)	(29,455)
Accumulated other comprehensive income (loss)
Activity Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(427,636)	4,092
Ending balance	$ (367,436)	$ (115,999)