Loan Portfolio and Allowance for Credit Losses, Based on Impairment Review Method (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	$ 0		$ 0
Collectively evaluated for impairment	46,914		46,032
Total ending allowance balance	46,914	$ 46,685	46,032	$ 45,285	$ 46,178
Loans [Abstract]
Individually evaluated for impairment	26,628		25,695
Collectively evaluated for impairment	4,860,183		4,707,506
Total loans	4,886,811		4,733,201
Commercial Loans [Member]
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	2,610		2,596
Total ending allowance balance	2,610	2,708	2,596	2,274	2,177
Loans [Abstract]
Individually evaluated for impairment	970		646
Collectively evaluated for impairment	250,464		230,365
Total loans	251,434		231,011
1 to 4 Family Residential Real Estate [Member]
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	44,067		43,271
Total ending allowance balance	44,067	43,766	43,271	42,880	43,931
Loans [Abstract]
Individually evaluated for impairment	25,546		24,967
Collectively evaluated for impairment	4,593,435		4,464,916
Total loans	4,618,981		4,489,883
Installment Loans [Member]
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	237		165
Total ending allowance balance	237	$ 211	165	$ 131	$ 70
Loans [Abstract]
Individually evaluated for impairment	112		82
Collectively evaluated for impairment	16,284		12,225
Total loans	$ 16,396		$ 12,307