Derivative Financial Instruments (Schedule Of Fair Value Of Derivative Financial Instruments) (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Derivative [Line Items]
Derivative Assets	$ 153,534	$ 165,008	$ 253,509
Derivative Liabilities	122,107	123,000	200,758
Interest rate contract
Derivative [Line Items]
Derivative Assets	139,701	152,493	206,236
Derivative Liabilities	120,079	119,907	196,091
Designated as hedging instrument
Derivative [Line Items]
Derivative Assets	20,645	48,783	50,541
Derivative Liabilities	5,077	16,242	40,730
Designated as hedging instrument | Interest rate contract | Interest rate derivatives designated as Cash Flow Hedges
Derivative [Line Items]
Derivative Assets	13,257	47,309	50,420
Derivative Liabilities	3,361	10,401	31,161
Designated as hedging instrument | Interest rate contract | Interest rate derivatives designated as Fair Value Hedges
Derivative [Line Items]
Derivative Assets	7,388	1,474	121
Derivative Liabilities	1,716	5,841	9,569
Not designated as hedging instrument
Derivative [Line Items]
Derivative Assets	132,889	116,225	202,968
Derivative Liabilities	117,030	106,758	160,028
Not designated as hedging instrument | Interest rate contract
Derivative [Line Items]
Derivative Assets	119,056	103,710	155,695
Derivative Liabilities	115,002	103,665	155,361
Not designated as hedging instrument | Interest rate lock commitments
Derivative [Line Items]
Derivative Assets	3,447	10,560	44,313
Derivative Liabilities	1,558	885	1,342
Not designated as hedging instrument | Forward commitments to sell mortgage loans
Derivative [Line Items]
Derivative Assets	10,063	1,625	2,920
Derivative Liabilities	147	1,878	3,283
Not designated as hedging instrument | Foreign exchange contracts
Derivative [Line Items]
Derivative Assets	323	330	40
Derivative Liabilities	$ 323	$ 330	$ 42