Derivative Financial Instruments (Summary Amounts Included In Consolidated Statement Of Income Related To Derivatives) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest rate swaps and caps | Trading (losses) gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ (75)	$ (55)	$ (392)	$ 89
Mortgage banking derivatives | Mortgage banking revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	1,026	(1,122)	1,089	858
Foreign exchange contracts | Trading (losses) gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	54	(18)	72	51
Covered call options | Fees from covered call options
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	0	627	2,427	2,893
Derivative contract held as economic hedge on MSRs | Mortgage banking revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ 82	$ 0	$ 1,002	$ 0