Fair Value Measurements - Estimated fair value of company's financial instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Federal funds sold	$ 30,830	$ 38,987
Interest bearing deposits with other banks	818,719	195,447
Investment securities	977,570	843,363
Bank owned life insurance	76,326	75,724
Derivative asset	4,306	311
Interest bearing deposits	823,607	863,856
Customer repurchase agreements	24,293	30,980
Derivative liability	5,216	611
Other equity investments
Investment securities	198	198
Carrying Value
Cash and due from banks	7,559	7,539
Federal funds sold	30,830	38,987
Interest bearing deposits with other banks	818,719	195,447
Investment securities	977,570	843,363
Federal Reserve and Federal Home Loan Bank stock	40,061	35,194
Loans held for sale	79,084	56,707
Loans	7,770,040	7,472,090
Bank owned life insurance	76,326	75,724
Cash Surrender Value, Fair Value Disclosure	14,541	14,697
Noninterest bearing deposits	2,384,108	2,064,367
Interest bearing deposits	4,780,160	3,876,985
Certificates of deposit	1,014,517	1,283,039
Customer repurchase agreements	24,293	30,980
Borrowings	567,980	467,687
Derivative liability	136	86
Carrying Value \| Interest Rate Swap
Derivative liability	910	203
Carrying Value \| Mortgage Banking Derivative
Derivative asset	6,015
Derivative liability		66
Carrying Value \| Interest Rate Caps
Derivative asset	4,233	280
Derivative liability	4,487	312
Fair Value
Cash and due from banks	7,559	7,539
Federal funds sold	30,830	38,987
Interest bearing deposits with other banks	818,719	195,447
Investment securities	977,570	843,363
Federal Reserve and Federal Home Loan Bank stock	40,061	35,194
Loans held for sale	79,084	56,707
Loans	7,733,020	7,550,249
Bank owned life insurance	76,326	75,724
Cash Surrender Value, Fair Value Disclosure	14,541	14,697
Noninterest bearing deposits	2,384,108	2,064,367
Interest bearing deposits	4,780,160	3,876,985
Certificates of deposit	1,033,703	1,291,688
Customer repurchase agreements	24,293	30,980
Borrowings	573,641	328,330
Derivative liability	136	86
Fair Value \| Interest Rate Swap
Derivative liability	910	203
Fair Value \| Mortgage Banking Derivative
Derivative asset	6,015
Derivative liability		66
Fair Value \| Interest Rate Caps
Derivative asset	4,233	280
Derivative liability	4,487	312
Fair Value \| Fair Value, Inputs, Level 1
Cash and due from banks	0	0
Federal funds sold	0	0
Interest bearing deposits with other banks	0	0
Investment securities	0	0
Federal Reserve and Federal Home Loan Bank stock	0	0
Loans held for sale	0	0
Loans		0
Bank owned life insurance	0	0
Cash Surrender Value, Fair Value Disclosure	0	0
Noninterest bearing deposits	0	0
Interest bearing deposits	0	0
Certificates of deposit	0	0
Customer repurchase agreements	0	0
Borrowings	0	0
Derivative liability	0	0
Fair Value \| Fair Value, Inputs, Level 1 \| Interest Rate Swap
Derivative liability	0	0
Fair Value \| Fair Value, Inputs, Level 1 \| Mortgage Banking Derivative
Derivative asset	0
Derivative liability		0
Fair Value \| Fair Value, Inputs, Level 1 \| Interest Rate Caps
Derivative asset	0	0
Derivative liability	0	0
Fair Value \| Fair Value, Inputs, Level 2
Cash and due from banks	7,559	7,539
Federal funds sold	30,830	38,987
Interest bearing deposits with other banks	818,719	195,447
Investment securities	976,070	832,432
Federal Reserve and Federal Home Loan Bank stock	40,061	35,194
Loans held for sale	79,084	56,707
Loans		0
Bank owned life insurance	76,326	75,724
Cash Surrender Value, Fair Value Disclosure	14,541	14,697
Noninterest bearing deposits	2,384,108	2,064,367
Interest bearing deposits	4,780,160	3,876,985
Certificates of deposit	1,033,703	1,291,688
Customer repurchase agreements	24,293	30,980
Borrowings	573,641	328,330
Derivative liability	136	86
Fair Value \| Fair Value, Inputs, Level 2 \| Interest Rate Swap
Derivative liability	910	203
Fair Value \| Fair Value, Inputs, Level 2 \| Mortgage Banking Derivative
Derivative asset	0
Derivative liability		0
Fair Value \| Fair Value, Inputs, Level 2 \| Interest Rate Caps
Derivative asset	4,233	280
Derivative liability	4,487	312
Fair Value \| Fair Value, Inputs, Level 3
Cash and due from banks	0	0
Federal funds sold	0	0
Interest bearing deposits with other banks	0	0
Investment securities	1,500	10,931
Federal Reserve and Federal Home Loan Bank stock	0	0
Loans held for sale	0	0
Loans	7,733,020	7,550,249
Bank owned life insurance	0	0
Cash Surrender Value, Fair Value Disclosure	0	0
Noninterest bearing deposits	0	0
Interest bearing deposits	0	0
Certificates of deposit	0	0
Customer repurchase agreements	0	0
Borrowings	0	0
Derivative liability	0	0
Fair Value \| Fair Value, Inputs, Level 3 \| Interest Rate Swap
Derivative liability	0	0
Fair Value \| Fair Value, Inputs, Level 3 \| Mortgage Banking Derivative
Derivative asset	6,015
Derivative liability		66
Fair Value \| Fair Value, Inputs, Level 3 \| Interest Rate Caps
Derivative asset	0	0
Derivative liability	$ 0	$ 0

The aggregate fair value of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.

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Fair value amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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The amount outstanding of funds lent to other depository institutions, securities brokers, or securities dealers in the form of Federal Funds sold; for example, immediately available funds lent under agreements or contracts that mature in one business day or roll over under a continuing contract, regardless of the nature of the transaction or the collateral involved, excluding overnight lending for commercial and industrial purposes. Also include Federal Funds sold under agreements to resell on a gross basis, excluding (1) sales of term Federal Funds, (2) due bills representing purchases of securities or other assets by the reporting bank that have not yet been delivered and similar instruments, (3) resale agreements that mature in more than one business day involving assets other than securities, and (4) yield maintenance dollar repurchase agreements.

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The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value portion of other liabilities.

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The aggregate value of all restricted investments.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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