Securities - Company's Securities' Gross Unrealized Losses and Fair Values, Aggregated by Length of Time Individual Securities Have Been in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Available-for-Sale Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		$ 29,904
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(2,720)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	$ 116,753	99,601
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(26,001)	(19,718)
Securities With Gross Unrealized Losses, Total Fair Value	116,753	129,505
Securities With Gross Unrealized Losses, Total Unrealized Losses	(26,001)	(22,438)
Held-to-Maturity Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value	96,415	444,969
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses	(4,961)	(15,099)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	327,585	675
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(22,034)	(153)
Securities With Gross Unrealized Losses, Total Fair Value	424,000	445,644
Securities With Gross Unrealized Losses, Total Unrealized Losses	(26,995)	(15,252)
U.S. Government Bonds
Available-for-Sale Securities:
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	2,713	2,689
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(276)	(296)
Securities With Gross Unrealized Losses, Total Fair Value	2,713	2,689
Securities With Gross Unrealized Losses, Total Unrealized Losses	(276)	(296)
Corporate Bonds
Available-for-Sale Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		13,138
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(1,186)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	23,190	10,221
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(2,609)	(1,279)
Securities With Gross Unrealized Losses, Total Fair Value	23,190	23,359
Securities With Gross Unrealized Losses, Total Unrealized Losses	(2,609)	(2,465)
Held-to-Maturity Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value	3,206	75,181
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses	(294)	(3,819)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	74,177
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(4,823)
Securities With Gross Unrealized Losses, Total Fair Value	77,383	75,181
Securities With Gross Unrealized Losses, Total Unrealized Losses	(5,117)	(3,819)
US Agency Bonds
Held-to-Maturity Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		24,620
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(380)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	24,496
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(504)
Securities With Gross Unrealized Losses, Total Fair Value	24,496	24,620
Securities With Gross Unrealized Losses, Total Unrealized Losses	(504)	(380)
Collateralized Mortgage Obligations
Available-for-Sale Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		4,537
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(300)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	32,989	33,240
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(7,657)	(6,426)
Securities With Gross Unrealized Losses, Total Fair Value	32,989	37,777
Securities With Gross Unrealized Losses, Total Unrealized Losses	(7,657)	(6,726)
Held-to-Maturity Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value	93,209	215,300
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses	(4,667)	(5,558)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	112,225
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(7,531)
Securities With Gross Unrealized Losses, Total Fair Value	205,434	215,300
Securities With Gross Unrealized Losses, Total Unrealized Losses	(12,198)	(5,558)
FHLMC Certificates
Available-for-Sale Securities:
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	8,537	9,634
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(1,904)	(1,676)
Securities With Gross Unrealized Losses, Total Fair Value	8,537	9,634
Securities With Gross Unrealized Losses, Total Unrealized Losses	(1,904)	(1,676)
Held-to-Maturity Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		3,177
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(115)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	3,565	675
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(358)	(153)
Securities With Gross Unrealized Losses, Total Fair Value	3,565	3,852
Securities With Gross Unrealized Losses, Total Unrealized Losses	(358)	(268)
FNMA Certificates
Available-for-Sale Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		12,111
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(1,230)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	49,219	43,817
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(13,552)	(10,041)
Securities With Gross Unrealized Losses, Total Fair Value	49,219	55,928
Securities With Gross Unrealized Losses, Total Unrealized Losses	(13,552)	(11,271)
Held-to-Maturity Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		126,691
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(5,227)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	113,122
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(8,818)
Securities With Gross Unrealized Losses, Total Fair Value	113,122	126,691
Securities With Gross Unrealized Losses, Total Unrealized Losses	(8,818)	(5,227)
GNMA Certificates
Available-for-Sale Securities:
Securities With Gross Unrealized Losses Less Than 12 Months, Fair Value		118
Securities With Gross Unrealized Losses Less Than 12 Months, Unrealized Losses		(4)
Securities With Gross Unrealized Losses 12 Months or More, Fair Value	105
Securities With Gross Unrealized Losses 12 Months or More, Unrealized Losses	(3)
Securities With Gross Unrealized Losses, Total Fair Value	105	118
Securities With Gross Unrealized Losses, Total Unrealized Losses	$ (3)	$ (4)