Derivative Financial Instruments (Summary Amounts Included In Consolidated Statement Of Income Related To Derivatives) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest rate swaps and caps | Trading (losses) gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ (428)	$ (191)
Mortgage banking derivatives | Mortgage banking revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	17,267	50
Foreign exchange contracts | Trading (losses) gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	(4)	(12)
Covered call options | Fees from covered call options
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	2,292	1,784
Derivative contract held as economic hedge on MSRs | Mortgage banking revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ 4,160	$ 0