Loans and Allowance for Credit Losses - Activity in ACL Related to Loans Held for Investment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 21,136	$ 19,088
Credit Loss Expense/ Provision (benefit)	(1,905)	2,060
Charge-offs	(163)	(165)
Recoveries	207	34
Ending Balance	14,764	21,017
Cumulative effect of adoption of accounting principles
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(4,511)
Commercial & industrial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	7,973	6,604
Credit Loss Expense/ Provision (benefit)	(101)	1,790
Charge-offs	(163)	(151)
Recoveries	185	26
Ending Balance	4,269	8,269
Commercial & industrial loans | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(7,973)
Commercial & industrial loans | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	4,348
Real estate construction one-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	679	643
Credit Loss Expense/ Provision (benefit)		0
Charge-offs		0
Recoveries		0
Ending Balance		643
Real estate construction one-to-four family | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(679)
Real estate construction other
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	1,179	1,017
Credit Loss Expense/ Provision (benefit)		262
Charge-offs		0
Recoveries		0
Ending Balance		1,279
Real estate construction other | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(1,179)
Real estate term owner occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2,625	2,188
Credit Loss Expense/ Provision (benefit)		242
Charge-offs		0
Recoveries		0
Ending Balance		2,430
Real estate term owner occupied | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(2,625)
Real estate term non-owner occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	5,133	5,180
Credit Loss Expense/ Provision (benefit)		311
Charge-offs		0
Recoveries		0
Ending Balance		5,491
Real estate term non-owner occupied | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(5,133)
Real estate term other
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	779	671
Credit Loss Expense/ Provision (benefit)		39
Charge-offs		0
Recoveries		1
Ending Balance		711
Real estate term other | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(779)
Consumer secured by 1st deeds of trust
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	261	270
Credit Loss Expense/ Provision (benefit)		4
Charge-offs		0
Recoveries		0
Ending Balance		274
Consumer secured by 1st deeds of trust | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(261)
Consumer other
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	400	436
Credit Loss Expense/ Provision (benefit)		24
Charge-offs		(14)
Recoveries		7
Ending Balance		453
Consumer other | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(400)
Other loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2,107	2,079
Credit Loss Expense/ Provision (benefit)	0	(612)
Charge-offs	0	0
Recoveries	0	0
Ending Balance	3	$ 1,467
Other loans | Cumulative effect of adoption of accounting principles, legacy segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	(2,107)
Other loans | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	3
Commercial real estate | Owner occupied properties
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(215)
Charge-offs	0
Recoveries	2
Ending Balance	3,366
Commercial real estate | Owner occupied properties | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	3,579
Commercial real estate | Non-owner occupied and multifamily properties
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(1,240)
Charge-offs	0
Recoveries	0
Ending Balance	3,704
Commercial real estate | Non-owner occupied and multifamily properties | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	4,944
Residential | 1-4 family residential properties secured by first liens
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	140
Charge-offs	0
Recoveries	0
Ending Balance	813
Residential | 1-4 family residential properties secured by first liens | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	673
Residential | 1-4 family residential properties secured by junior liens and revolving secured by 1-4 family first liens
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(87)
Charge-offs	0
Recoveries	10
Ending Balance	342
Residential | 1-4 family residential properties secured by junior liens and revolving secured by 1-4 family first liens | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	419
Residential | 1-4 family residential construction loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(194)
Charge-offs	0
Recoveries	0
Ending Balance	260
Residential | 1-4 family residential construction loans | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	454
Other construction, land development and raw land loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(173)
Charge-offs	0
Recoveries	0
Ending Balance	1,821
Other construction, land development and raw land loans | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	1,994
Obligations of states and political subdivisions in the US
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(8)
Charge-offs	0
Recoveries	0
Ending Balance	36
Obligations of states and political subdivisions in the US | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	44
Agricultural production, including commercial fishing
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(11)
Charge-offs	0
Recoveries	8
Ending Balance	46
Agricultural production, including commercial fishing | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	49
Consumer
Financing Receivable, Allowance for Credit Loss [Line Items]
Credit Loss Expense/ Provision (benefit)	(16)
Charge-offs	0
Recoveries	2
Ending Balance	104
Consumer | Cumulative effect of adoption of accounting principles, revised segmentation
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 118