Fair Value Measurement - Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Carrying Amount
Financial assets:
Cash and cash equivalents	$ 128,488	$ 108,408
Investment securities:
HTM, at carrying value	908	907
Mortgage-backed securities:
HTM, at carrying value	93,942	108,091
Federal Home Loan Bank stock, at cost	28,081	25,259
Equity investments	5,817	5,811
Loans, net of allowance for loan losses	3,599,433	3,608,773
Loans held for sale	2,510	3,695
Financial liabilities:
Deposits	5,156,167	4,932,322
Other borrowings	23,783	23,172
FHLB borrowings	721,368	832,527
Subordinated notes, net of unamortized debt issuance costs	197,312	197,251
Trust preferred subordinated debentures, net of unamortized debt issuance costs	60,258	60,255
Estimated Fair Value
Financial assets:
Cash and cash equivalents	128,488	108,408
Investment securities:
HTM, at carrying value	913	920
Mortgage-backed securities:
HTM, at carrying value	100,455	117,278
Federal Home Loan Bank stock, at cost	28,081	25,259
Equity investments	5,817	5,811
Loans, net of allowance for loan losses	3,765,725	3,784,291
Loans held for sale	2,510	3,695
Financial liabilities:
Deposits	5,158,210	4,936,188
Other borrowings	23,783	23,172
FHLB borrowings	732,425	854,865
Subordinated notes, net of unamortized debt issuance costs	201,322	198,391
Trust preferred subordinated debentures, net of unamortized debt issuance costs	49,267	51,993
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	128,488	108,408
Investment securities:
HTM, at carrying value	0	0
Mortgage-backed securities:
HTM, at carrying value	0	0
Federal Home Loan Bank stock, at cost	0	0
Equity investments	0	0
Loans, net of allowance for loan losses	0	0
Loans held for sale	0	0
Financial liabilities:
Deposits	0	0
Other borrowings	0	0
FHLB borrowings	0	0
Subordinated notes, net of unamortized debt issuance costs	0	0
Trust preferred subordinated debentures, net of unamortized debt issuance costs	0	0
Estimated Fair Value | Level 2
Financial assets:
Cash and cash equivalents	0	0
Investment securities:
HTM, at carrying value	913	920
Mortgage-backed securities:
HTM, at carrying value	100,455	117,278
Federal Home Loan Bank stock, at cost	28,081	25,259
Equity investments	5,817	5,811
Loans, net of allowance for loan losses	0	0
Loans held for sale	2,510	3,695
Financial liabilities:
Deposits	5,158,210	4,936,188
Other borrowings	23,783	23,172
FHLB borrowings	732,425	854,865
Subordinated notes, net of unamortized debt issuance costs	201,322	198,391
Trust preferred subordinated debentures, net of unamortized debt issuance costs	49,267	51,993
Estimated Fair Value | Level 3
Financial assets:
Cash and cash equivalents	0	0
Investment securities:
HTM, at carrying value	0	0
Mortgage-backed securities:
HTM, at carrying value	0	0
Federal Home Loan Bank stock, at cost	0	0
Equity investments	0	0
Loans, net of allowance for loan losses	3,765,725	3,784,291
Loans held for sale	0	0
Financial liabilities:
Deposits	0	0
Other borrowings	0	0
FHLB borrowings	0	0
Subordinated notes, net of unamortized debt issuance costs	0	0
Trust preferred subordinated debentures, net of unamortized debt issuance costs	$ 0	$ 0