Loan Portfolio and Allowance for Credit Losses, Based on Impairment Review Method (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	$ 0		$ 0
Collectively evaluated for impairment	45,285		44,267
Total ending allowance balance	45,285		44,267	$ 50,155		$ 49,595
Total ending allowance balance		$ 46,178	44,267	50,155	$ 49,991
Loans [Abstract]
Individually evaluated for impairment	27,013		18,504
Collectively evaluated for impairment	4,513,546		4,420,275
Total loans	4,540,559
Total loans			4,438,779
Commercial [Member]
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	2,274		3,135
Total ending allowance balance	2,274		3,135	4,106		4,140
Total ending allowance balance		2,177	3,135	4,106	4,052
Loans [Abstract]
Individually evaluated for impairment	319		232
Collectively evaluated for impairment	199,567		199,968
Total loans	199,886
Total loans			200,200
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	42,880		40,689
Total ending allowance balance	42,880		40,689	45,617		44,950
Total ending allowance balance		43,931	40,689	45,617	45,507
Loans [Abstract]
Individually evaluated for impairment	26,673		18,272
Collectively evaluated for impairment	4,303,742		4,210,891
Total loans	4,330,415
Total loans			4,229,163
Installment [Member]
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	131		443
Total ending allowance balance	131		443	432		$ 505
Total ending allowance balance		$ 70	443	$ 432	$ 432
Loans [Abstract]
Individually evaluated for impairment	21		0
Collectively evaluated for impairment	10,237		9,416
Total loans	$ 10,258
Total loans			$ 9,416