Loans and Allowance for Credit Losses - Loans Individually and Collectively Evaluated for Impairment Prior to Adoption of ASU 2016-13 (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			$ 18,028
Loan Evaluation, Collectively			1,426,022
Total	$ 1,450,657		1,444,050
ALLL Allocations, Individually			13
ALLL Allocations, Collectively			21,123
Total	13,816	$ 14,539	21,136	$ 21,683	$ 20,653	$ 19,088
Commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			7,786
Loan Evaluation, Collectively			764,682
Total	504,305		772,468
ALLL Allocations, Individually			13
ALLL Allocations, Collectively			7,960
Total	3,982	4,291	7,973	8,195	7,366	6,604
Real estate construction one-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			702
Loan Evaluation, Collectively			37,478
Total			38,180
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			679
Total			679	700	690	643
Real estate construction other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			0
Loan Evaluation, Collectively			79,403
Total			79,403
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			1,179
Total			1,179	1,273	1,215	1,017
Real estate term owner occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			6,962
Loan Evaluation, Collectively			155,762
Total			162,724
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			2,625
Total			2,625	2,469	2,533	2,188
Real estate term non-owner occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			770
Loan Evaluation, Collectively			306,477
Total			307,247
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			5,133
Total			5,133	5,482	5,421	5,180
Real estate term other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			1,467
Loan Evaluation, Collectively			44,763
Total			46,230
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			779
Total			779	758	702	671
Consumer secured by 1st deeds of trust
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			259
Loan Evaluation, Collectively			15,289
Total			15,548
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			261
Total			261	256	258	270
Consumer other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			82
Loan Evaluation, Collectively			22,168
Total			22,250
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			400
Total			400	443	447	436
Other loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan Evaluation, Individually			0
Loan Evaluation, Collectively			0
Total	3,020		0
ALLL Allocations, Individually			0
ALLL Allocations, Collectively			2,107
Total	$ 6	$ 6	$ 2,107	$ 2,107	$ 2,021	$ 2,079