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, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest rate swaps and caps | Trading (losses) gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ (55)	$ (94)	$ 89	$ (762)
Mortgage banking derivatives | Mortgage banking revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	(1,122)	708	858	1,398
Covered call options | Fees from covered call options
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	627	1,143	2,893	2,792
Foreign exchange contracts | Trading (losses) gains, net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ (18)	$ (23)	$ 51	$ (115)