Fair Value of Financial Instruments and Fair Value Measurements - Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financial Assets
Debt securities available for sale	$ 881,859	$ 785,977
Interest receivable	17,029	18,525
FHLB stock	13,773	15,381
Derivative assets	12,500	1,848
Financial Liabilities
Interest-bearing deposits	995,762	962,830
Short-term borrowings	129,489	139,349
Finance leases payable	1,194	1,225
Carrying Amount
Financial Assets
Cash and cash equivalents	125,545	73,484
Debt securities available for sale	881,859	785,977
Loans held for sale	9,483	5,400
Loans held for investment, net	3,374,575	3,422,187
Interest receivable	17,029	18,525
FHLB stock	13,773
Derivative assets	12,500	1,848
Financial Liabilities
Non-interest-bearing demand	637,127	662,209
Interest-bearing deposits	3,222,717	3,066,446
Short-term borrowings	129,489	139,349
Finance leases payable	1,194	1,224
Federal Home Loan Bank borrowings	125,673	145,700
Junior subordinated notes issued to capital trusts	41,631	41,587
Subordinated debentures	10,894	10,899
Other long-term debt	30,482	32,250
Derivative liabilities	16,305	3,242
Estimated Fair Value
Financial Assets
Cash and cash equivalents	125,545	73,484
Debt securities available for sale	881,859	785,977
Loans held for sale	9,646	5,476
Loans held for investment, net	3,414,068	3,427,952
Interest receivable	17,029	18,525
FHLB stock	13,773	15,381
Derivative assets	12,500	1,848
Financial Liabilities
Non-interest-bearing demand	637,127	662,209
Interest-bearing deposits	3,231,800	3,066,427
Short-term borrowings	129,489	139,349
Finance leases payable	1,194	1,224
Federal Home Loan Bank borrowings	129,372	146,913
Junior subordinated notes issued to capital trusts	34,655	39,391
Subordinated debentures	11,066	11,083
Other long-term debt	30,482	32,250
Derivative liabilities	16,305	3,242
Level 1 | Estimated Fair Value
Financial Assets
Cash and cash equivalents	125,545	73,484
Debt securities available for sale	0	0
Interest receivable	0	0
FHLB stock	0	0
Derivative assets	0	0
Financial Liabilities
Non-interest-bearing demand	637,127	662,209
Interest-bearing deposits	2,193,344	2,113,000
Short-term borrowings	129,489	139,349
Finance leases payable	0	0
Federal Home Loan Bank borrowings	0	0
Junior subordinated notes issued to capital trusts	0	0
Subordinated debentures	0	0
Other long-term debt	0	0
Derivative liabilities	0	0
Level 2 | Estimated Fair Value
Financial Assets
Debt securities available for sale	881,859	785,977
Loans held for sale	9,646	5,476
Interest receivable	17,029	18,525
FHLB stock	13,773	15,381
Derivative assets	12,500	1,848
Financial Liabilities
Interest-bearing deposits	1,038,456	953,427
Finance leases payable	1,194	1,224
Federal Home Loan Bank borrowings	129,372	146,913
Junior subordinated notes issued to capital trusts	34,655	39,391
Subordinated debentures	11,066	11,083
Other long-term debt	30,482	32,250
Derivative liabilities	16,305	3,242
Level 3 | Estimated Fair Value
Financial Assets
Loans held for sale	0	0
Loans held for investment, net	3,414,068	3,427,952
Derivative assets	0	0
Financial Liabilities
Finance leases payable	0	0
Subordinated debentures	0	0
Other long-term debt	0	0
Derivative liabilities	$ 0	$ 0