Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 1,363,823	$ 1,007,834
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	43,947	52,235
Securities Available-for-Sale, Gross Unrealized Holding Losses	3,502	728
Debt Securities, Available-for-sale	1,404,268	1,059,341
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	278,104	279,245
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	23,726	25,973
Debt Securities, Available-for-sale	301,830	305,218
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	856,255	726,589
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	20,132	26,248
Securities Available-for-Sale, Gross Unrealized Holding Losses	3,479	728
Debt Securities, Available-for-sale	872,908	752,109
Corporate Debt Securities
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	2,250	2,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	82	14
Debt Securities, Available-for-sale	2,332	$ 2,014
Collateralized Loan Obligations
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	227,214
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	7
Securities Available-for-Sale, Gross Unrealized Holding Losses	23
Debt Securities, Available-for-sale	$ 227,198