Derivative Financial Instruments (Rollforward Of Amounts In Accumulated Other Comprehensive Income Related To Interest Rate Swaps Designated As Cash Flow Hedges) (Detail) - Interest Rate Contract - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Rollforward of AOCI from Cash Flow Hedging Derivatives [Roll Forward]
Unrealized gain (loss) at beginning of period	$ 8,559	$ (3,051)	$ 6,944	$ (3,529)
Amount reclassified from accumulated other comprehensive loss to interest expense on deposits and junior subordinated debentures	821	832	1,037	1,555
Amount of (loss) gain recognized in other comprehensive income	1,131	1,355	(268)	1,600
Unrealized gain (loss) at end of period	$ 8,249	$ (3,574)	$ 8,249	$ (3,574)