Shareholders' Equity And Earnings Per Share (Other Comprehensive Income Reclassified from AOCI) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
(Losses) gains on investment securities, net	$ 0	$ 584	$ 251	$ 794
Income tax expense	(37,148)	(39,041)	(83,437)	(92,752)
Interest on deposits	18,985	24,298	33,839	52,242
Interest on junior subordinated debentures	2,050	2,724	3,617	5,428
Net income	94,513	105,109	221,904	258,257
Reclassification Out of Accumulated Other Comprehensive Income | Accumulated unrealized gains on securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
(Losses) gains on investment securities, net	0	584	250	794
Income before taxes	0	584	250	794
Income tax expense	0	(157)	(67)	(213)
Net income	0	427	183	581
Reclassification Out of Accumulated Other Comprehensive Income | Accumulated unrealized losses on derivative instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income before taxes	(1,012)	(6,866)	(6,365)	(13,562)
Income tax expense	270	1,830	1,697	3,614
Interest on deposits	657	5,054	5,476	9,951
Interest on other borrowings	355	653	889	1,322
Interest on junior subordinated debentures	0	1,159	0	2,289
Net income	$ (742)	$ (5,036)	$ (4,668)	$ (9,948)