Fair Values Of Assets And Liabilities (Summary Of Assets Measured At Fair Value On A Nonrecurring Basis) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans—collateral based	$ 95,976	$ 95,976	$ 101,255	$ 103,357
Fair Value Losses Recognized, Impaired loans—collateral based	3,897	6,230
Fair Value Losses Recognized, Other real estate owned	2,293	3,380
Fair Value Losses Recognized, Total	6,190	9,610
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans—collateral based	67,837	67,837
Other real estate owned	51,046	51,046
Total	118,883	118,883
Fair Value, Measurements, Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans—collateral based	0	0
Other real estate owned	0	0
Total	0	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans—collateral based	0	0
Other real estate owned	0	0
Total	0	0
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans—collateral based	67,837	67,837
Other real estate owned	51,046	51,046
Total	$ 118,883	$ 118,883