Investment Securities, Securities Held-to-Maturity (Details) - USD ($) $ in Thousands		Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Amortized cost		$ 769,443		$ 817,688
Gross unrecognized gains		46		137
Gross unrecognized losses		158,536		146,240
Fair value		610,953		671,585
Allowance for credit losses		450		450		$ 393
Mortgage-backed Securities [Member]
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Amortized cost	[1]	626,427		664,728
Gross unrecognized gains	[1]	0		30
Gross unrecognized losses	[1]	143,544		132,043
Fair value	[1]	482,883		532,715
Allowance for credit losses		0	[1]	0	[1]	0
Collateralized Mortgage Obligations [Member]
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Amortized cost	[1]	68,377		74,170
Gross unrecognized gains	[1]	0		0
Gross unrecognized losses	[1]	13,876		14,017
Fair value	[1]	54,501		60,153
Allowance for credit losses		0	[1]	0	[1]	0
Municipal Securities [Member]
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Amortized cost		74,639		78,790
Gross unrecognized gains		46		107
Gross unrecognized losses		1,116		180
Fair value		73,569		78,717
Allowance for credit losses		$ 450		$ 450		$ 393

[1] All mortgage-backed securities and collateralized mortgage obligations were issued by an agency or government sponsored entity of the U.S. Government.