Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 1,519,098	$ 1,007,834
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	39,632	52,235
Securities Available-for-Sale, Gross Unrealized Holding Losses	5,512	728
Debt Securities, Available-for-sale	1,553,218	1,059,341
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	277,527	279,245
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	21,567	25,973
Debt Securities, Available-for-sale	299,094	305,218
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	844,128	726,589
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	17,876	26,248
Securities Available-for-Sale, Gross Unrealized Holding Losses	4,855	728
Debt Securities, Available-for-sale	857,149	752,109
Corporate Debt Securities
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	9,250	2,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	43	14
Debt Securities, Available-for-sale	9,293	$ 2,014
Collateralized Loan Obligations
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	388,193
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	146
Securities Available-for-Sale, Gross Unrealized Holding Losses	657
Debt Securities, Available-for-sale	$ 387,682