Accumulated Other Comprehensive Income or Loss and Earnings Per Share (Other Comprehensive Income Reclassified from AOCI) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Gains (losses) on investment securities, net	$ 0	$ 0	$ 560	$ 251
Income tax expense	56,680	37,148	120,032	83,437
Interest on deposits	213,495	18,985	358,297	33,839
Net income	154,750	94,513	334,948	221,904
Reclassification Out of Accumulated Other Comprehensive Income | Accumulated unrealized gains on securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Gains (losses) on investment securities, net	2	0	562	250
Income before taxes	2	0	562	250
Income tax expense	(1)	0	(152)	(67)
Net income	1	0	410	183
Reclassification Out of Accumulated Other Comprehensive Income | Accumulated unrealized gains on derivative instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income before taxes	(14,092)	(1,012)	(17,664)	(6,365)
Income tax expense	3,755	270	4,707	1,697
Interest on Loans	18,661	0	27,733	0
Interest on deposits	(4,657)	657	(10,245)	5,476
Interest on other borrowings	88	355	176	889
Net income	$ (10,337)	$ (742)	$ (12,957)	$ (4,668)