Disclosures about Fair Value of Financial Instruments - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financial Assets
Available-for-sale securities	$ 649,901	$ 739,473
Restricted equity securities	20,923	17,278
Carrying Amount
Financial Assets
Cash and cash equivalents	223,636	187,320
Available-for-sale securities	652,146	741,634
Loans, net of allowance for loan losses	4,401,774	3,795,348
Restricted equity securities	20,923	17,278
Interest receivable	19,003	15,716
Derivative assets	27,873	9,838
Total financial assets	5,345,355	4,767,134
Financial Liabilities
Deposits	4,492,549	3,923,759
Federal funds purchased and repurchase agreements	13,531	14,921
Federal Home Loan Bank advances	336,100	358,743
Other borrowings	952	921
Interest payable	2,550	4,584
Derivative liabilities	27,949	9,907
Total financial liabilities	4,873,631	4,312,835
Estimate of Fair Value Measurement
Financial Assets
Cash and cash equivalents	223,636	187,320
Available-for-sale securities	652,146	741,634
Loans, net of allowance for loan losses	4,386,027	3,810,818
Restricted equity securities	20,923	17,278
Interest receivable	19,003	15,716
Derivative assets	27,873	9,838
Total financial assets	5,329,608	4,782,604
Financial Liabilities
Deposits	4,538,838	3,928,838
Federal funds purchased and repurchase agreements	13,531	14,921
Federal Home Loan Bank advances	353,309	357,859
Other borrowings	1,897	2,147
Interest payable	2,550	4,584
Derivative liabilities	27,949	9,907
Total financial liabilities	4,938,074	4,318,256
Estimate of Fair Value Measurement | Level 1
Financial Assets
Cash and cash equivalents	223,636	187,320
Available-for-sale securities	0	0
Loans, net of allowance for loan losses	0	0
Restricted equity securities	0	0
Interest receivable	0	0
Derivative assets	0	0
Total financial assets	223,636	187,320
Financial Liabilities
Deposits	754,172	521,826
Federal funds purchased and repurchase agreements	0	0
Federal Home Loan Bank advances	0	0
Other borrowings	0	0
Interest payable	0	0
Derivative liabilities	0	0
Total financial liabilities	754,172	521,826
Estimate of Fair Value Measurement | Level 2
Financial Assets
Cash and cash equivalents	0	0
Available-for-sale securities	652,146	741,634
Loans, net of allowance for loan losses	0	0
Restricted equity securities	0	0
Interest receivable	19,003	15,716
Derivative assets	27,873	9,838
Total financial assets	699,022	767,188
Financial Liabilities
Deposits	0	0
Federal funds purchased and repurchase agreements	13,531	14,921
Federal Home Loan Bank advances	353,309	357,859
Other borrowings	1,897	2,147
Interest payable	2,550	4,584
Derivative liabilities	27,949	9,907
Total financial liabilities	399,236	389,418
Estimate of Fair Value Measurement | Level 3
Financial Assets
Cash and cash equivalents	0	0
Available-for-sale securities	0	0
Loans, net of allowance for loan losses	4,386,027	3,810,818
Restricted equity securities	20,923	17,278
Interest receivable	0	0
Derivative assets	0	0
Total financial assets	4,406,950	3,828,096
Financial Liabilities
Deposits	3,784,666	3,407,012
Federal funds purchased and repurchase agreements	0	0
Federal Home Loan Bank advances	0	0
Other borrowings	0	0
Interest payable	0	0
Derivative liabilities	0	0
Total financial liabilities	$ 3,784,666	$ 3,407,012