Derivative Financial Instruments (Summary Amounts Included In Consolidated Statement Of Income Related To Derivatives) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest rate swaps and caps | Trading gains (losses), net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ (9)	$ (365)	$ 144	$ (668)
Mortgage banking derivatives | Mortgage banking revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	562	(48)	1,980	690
Covered call options | Fees from covered call options
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	669	890	2,266	1,649
Foreign exchange contracts | Trading gains (losses), net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ 112	$ (64)	$ 69	$ (92)