Derivative Financial Instruments (Rollforward Of Amounts In Accumulated Other Comprehensive Income Related To Interest Rate Swaps Designated As Cash Flow Hedges) (Detail) - Interest rate contract - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Rollforward of AOCI from Cash Flow Hedging Derivatives [Roll Forward]
Unrealized gain at beginning of period	$ 10,026	$ 36,908
Amount reclassified from accumulated other comprehensive income or loss to interest income or expense on deposits, loans, and other borrowings	3,572	5,353
Amount of gain recognized in other comprehensive income or loss	31,094	34,128
Unrealized gain at end of period	$ 44,692	$ 76,389