Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financial assets:
Securities AFS	$ 413,246	$ 335,573
Equity securities	4,032	3,936
Nonmarketable equity securities	3,441	1,350
Level 1
Financial assets:
Cash and due from banks	31,097	25,937
Interest-bearing deposits in other banks	210,254	107,355
Securities AFS	0	0
Equity securities	4,032	3,936
Nonmarketable equity securities	0	0
Loans HFS	0	0
Loans HFI, net of allowance	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Accrued interest payable	0	0
Level 2
Financial assets:
Cash and due from banks	0	0
Interest-bearing deposits in other banks	0	0
Securities AFS	413,246	335,573
Equity securities	0	0
Nonmarketable equity securities	3,441	1,350
Loans HFS	14,578	5,089
Loans HFI, net of allowance	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	2,074,560	1,721,286
Accrued interest payable	1,994	2,222
Level 3
Financial assets:
Cash and due from banks	0	0
Interest-bearing deposits in other banks	0	0
Securities AFS	0	0
Equity securities	0	0
Nonmarketable equity securities	0	0
Loans HFS	0	0
Loans HFI, net of allowance	1,606,075	1,426,163
Accrued interest receivable	6,492	5,251
Financial liabilities:
Deposits	0	0
Accrued interest payable	0	0
Carrying Amount
Financial assets:
Cash and due from banks	31,097	25,937
Interest-bearing deposits in other banks	210,254	107,355
Securities AFS	413,246	335,573
Equity securities	4,032	3,936
Nonmarketable equity securities	3,441	1,350
Loans HFS	14,578	5,089
Loans HFI, net of allowance	1,600,416	1,424,987
Accrued interest receivable	6,492	5,251
Financial liabilities:
Deposits	2,069,322	1,721,120
Accrued interest payable	1,994	2,222
Fair Value
Financial assets:
Cash and due from banks	31,097	25,937
Interest-bearing deposits in other banks	210,254	107,355
Securities AFS	413,246	335,573
Equity securities	4,032	3,936
Nonmarketable equity securities	3,441	1,350
Loans HFS	14,578	5,089
Loans HFI, net of allowance	1,606,075	1,426,163
Accrued interest receivable	6,492	5,251
Financial liabilities:
Deposits	2,074,560	1,721,286
Accrued interest payable	$ 1,994	$ 2,222