Fair Value Disclosures - Estimated Fair Value of Company's Financial Assets and Financial Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financial assets:
Cash and cash equivalents, Carrying Amount	$ 288,278	$ 197,880
Securities - held to maturity, Carrying Amount	6,096	8,417
Loans not previously presented Carrying Amount	4,810,731	4,170,604
FHLB and other restricted stock, Carrying Amount	18,464	19,860
Accrued interest receivable, Carrying Amount	20,254	20,322
Cash and cash equivalents, Fair Value	288,278	197,880
Securities - Held to maturity, Fair value	5,473	6,907
Loans not previously presented Fair Value	4,791,092	4,170,051
Accrued interest receivable, Fair Value	20,254	20,322
Financial liabilities:
Deposits, Carrying Amount	4,248,101	3,789,906
Customer repurchase agreements, Carrying Amount	14,192	2,033
Federal Home Loan Bank advances, Carrying Amount	435,000	430,000
Paycheck Protection Program Liquidity Facility	223,713	0
Subordinated notes, Carrying Amount	87,455	87,327
Junior subordinated debentures	39,944	39,566
Accrued interest payable, Carrying Amount	6,006	9,367
Deposits, Fair Value	4,254,371	3,793,603
Customer repurchase agreements, Fair Value	14,192	2,033
Federal Home Loan Bank advances, Fair Value	435,000	430,000
Paycheck Protection Program Liquidity Facility, Fair Value	223,713
Subordinated notes, Fair Value	89,806	93,877
Junior subordinated debentures, Fair Value	40,135	40,700
Accrued interest payable, Fair Value	6,006	9,367
Level 1
Financial assets:
Cash and cash equivalents, Fair Value	288,278	197,880
Securities - Held to maturity, Fair value	0	0
Loans not previously presented Fair Value	197,859	83,454
Accrued interest receivable, Fair Value	20,254	20,322
Financial liabilities:
Deposits, Fair Value	0	0
Customer repurchase agreements, Fair Value	0	0
Federal Home Loan Bank advances, Fair Value	0	0
Paycheck Protection Program Liquidity Facility, Fair Value	0
Subordinated notes, Fair Value	0	0
Junior subordinated debentures, Fair Value	0	0
Accrued interest payable, Fair Value	6,006	9,367
Level 2
Financial assets:
Cash and cash equivalents, Fair Value	0	0
Securities - Held to maturity, Fair value	0	0
Loans not previously presented Fair Value	0	0
Accrued interest receivable, Fair Value	0	0
Financial liabilities:
Deposits, Fair Value	4,254,371	3,793,603
Customer repurchase agreements, Fair Value	14,192	2,033
Federal Home Loan Bank advances, Fair Value	435,000	430,000
Paycheck Protection Program Liquidity Facility, Fair Value	223,713
Subordinated notes, Fair Value	89,806	93,877
Junior subordinated debentures, Fair Value	40,135	40,700
Accrued interest payable, Fair Value	0	0
Level 3
Financial assets:
Cash and cash equivalents, Fair Value	0	0
Securities - Held to maturity, Fair value	5,473	6,907
Loans not previously presented Fair Value	4,593,233	4,086,597
Accrued interest receivable, Fair Value	0	0
Financial liabilities:
Deposits, Fair Value	0	0
Customer repurchase agreements, Fair Value	0	0
Federal Home Loan Bank advances, Fair Value	0	0
Paycheck Protection Program Liquidity Facility, Fair Value	0
Subordinated notes, Fair Value	0	0
Junior subordinated debentures, Fair Value	0	0
Accrued interest payable, Fair Value	$ 0	$ 0

Accrued interest payable fair value disclosure.

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Accrued interest receivable fair value disclosure.

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Debt Securities, Held-to-Maturity, Amortized Cost, After Allowance For Credit Loss

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Federal home loan bank and other restricted stock at cost.

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Junior subordinated notes fair value disclosure.

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Loans and leases receivable reported amount not previously presented.

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Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Amount 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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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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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Amount of interest payable on debt, including, but not limited to, trade payables.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Fair value portion of contractual arrangement with a lender under which borrowings can be made up to a specific amount at any point in time.

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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 securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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