Securities (Securities Held to Maturity with Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair value	$ 439,510	$ 1,836,592
Held to maturity, Losses less than 12 months, Gross unrealized losses	13,550	112,063
Held to maturity, Losses 12 months or longer, Fair value	1,990,777	725,298
Held to maturity, Losses 12 months or longer, Gross unrealized losses	284,108	125,808
Held to maturity, Total, Fair value	2,430,287	2,561,890
Held to maturity, Total, Gross unrealized losses	297,658	237,871
U.S. Treasury And Government Agency Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair value	29,314	145,893
Held to maturity, Losses less than 12 months, Gross unrealized losses	1,310	13,245
Held to maturity, Losses 12 months or longer, Fair value	329,004	226,499
Held to maturity, Losses 12 months or longer, Gross unrealized losses	58,696	35,799
Held to maturity, Total, Fair value	358,318	372,392
Held to maturity, Total, Gross unrealized losses	60,006	49,044
Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair value	410,196	560,288
Held to maturity, Losses less than 12 months, Gross unrealized losses	12,240	8,878
Held to maturity, Losses 12 months or longer, Fair value	218,545	64,346
Held to maturity, Losses 12 months or longer, Gross unrealized losses	26,828	17,680
Held to maturity, Total, Fair value	628,741	624,634
Held to maturity, Total, Gross unrealized losses	39,068	26,558
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair value		391,146
Held to maturity, Losses less than 12 months, Gross unrealized losses		30,515
Held to maturity, Losses 12 months or longer, Fair value	584,996	270,800
Held to maturity, Losses 12 months or longer, Gross unrealized losses	88,902	42,017
Held to maturity, Total, Fair value	584,996	661,946
Held to maturity, Total, Gross unrealized losses	88,902	72,532
Commercial Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair value		697,827
Held to maturity, Losses less than 12 months, Gross unrealized losses		56,899
Held to maturity, Losses 12 months or longer, Fair value	826,028	163,653
Held to maturity, Losses 12 months or longer, Gross unrealized losses	107,231	30,312
Held to maturity, Total, Fair value	826,028	861,480
Held to maturity, Total, Gross unrealized losses	107,231	87,211
Collateralized Mortgage Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, Losses less than 12 months, Fair value		41,438
Held to maturity, Losses less than 12 months, Gross unrealized losses		2,526
Held to maturity, Losses 12 months or longer, Fair value	32,204
Held to maturity, Losses 12 months or longer, Gross unrealized losses	2,451
Held to maturity, Total, Fair value	32,204	41,438
Held to maturity, Total, Gross unrealized losses	$ 2,451	$ 2,526