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Loans and Allowance for Loan and Lease Losses - Loan Balances and Related ALLL (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss
Allowance for loans individually evaluated for impairment	$ 911		$ 561
Allowance for loans collectively evaluated for impairment	17,255		13,050
Total allowance	18,166	$ 17,520	13,611	$ 11,474	$ 11,514	$ 13,506
Loans individually evaluated for impairment	23,843		15,563
Loans collectively evaluated for impairment	1,345,904		1,110,776
Total	1,369,747		1,126,339
Commercial
Financing Receivable, Allowance for Credit Loss
Allowance for loans individually evaluated for impairment	911		561
Allowance for loans collectively evaluated for impairment	10,576		8,322
Total allowance	11,487	11,218	8,883	6,809	6,895	8,071
Loans individually evaluated for impairment	17,968		9,056
Loans collectively evaluated for impairment	680,312		400,364
Total	698,280		409,420
Real Estate
Financing Receivable, Allowance for Credit Loss
Allowance for loans individually evaluated for impairment	0		0
Allowance for loans collectively evaluated for impairment	4,733		2,897
Total allowance	4,733	4,368	2,897	2,790	2,709	3,643
Loans individually evaluated for impairment	5,875		6,507
Loans collectively evaluated for impairment	557,410		597,782
Total	563,285		604,289
Construction and land development loans
Financing Receivable, Allowance for Credit Loss
Allowance for loans individually evaluated for impairment	0		0
Allowance for loans collectively evaluated for impairment	77		34
Total allowance	77	55	34	119	295	426
Loans individually evaluated for impairment	0		0
Loans collectively evaluated for impairment	7,247		2,981
Total	7,247		2,981
Consumer and Single Family Mortgages
Financing Receivable, Allowance for Credit Loss
Allowance for loans individually evaluated for impairment	0		0
Allowance for loans collectively evaluated for impairment	1,869		1,797
Total allowance	1,869	1,879	1,797	1,756	1,486	1,290
Loans individually evaluated for impairment	0		0
Loans collectively evaluated for impairment	100,935		109,649
Total	100,935		109,649
Unallocated
Financing Receivable, Allowance for Credit Loss
Allowance for loans individually evaluated for impairment	0		0
Allowance for loans collectively evaluated for impairment	0		0
Total allowance	0	$ 0	0	$ 0	$ 129	$ 76
Loans individually evaluated for impairment	0		0
Loans collectively evaluated for impairment	0		0
Total	$ 0		$ 0