Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets
Securities available-for-sale	$ 323,565	$ 404,825
Securities held-to-maturity	332,452	368,107
Federal Home Loan Bank, Federal Reserve Bank stock and other investments, at cost	33,509	29,842
I/O strips receivables	482	503
Liabilities
Subordinated Debt.	39,646	39,554
Significant Other Observable Inputs (Level 2)
Assets
I/O strips receivables	482	503
Carrying amount
Assets
Cash and cash equivalents	925,900	457,370
Securities available-for-sale	323,565	404,825
Securities held-to-maturity	322,677	366,560
Loans (including loans held-for-sale), net	2,645,269	2,511,611
Federal Home Loan Bank, Federal Reserve Bank stock and other investments, at cost	33,509	29,842
Accrued interest receivable	10,041	10,915
I/O strips receivables	482	503
Liabilities
Time deposits	150,261	168,034
Other deposits	3,749,965	3,246,734
Subordinated Debt.	39,646	39,554
Accrued interest payable	585	707
Carried at fair value
Assets
Cash and cash equivalents	925,900	457,370
Securities available-for-sale	323,565	404,825
Securities held-to-maturity	332,452	368,107
Loans (including loans held-for-sale), net	2,635,366	2,513,329
Accrued interest receivable	10,041	10,915
I/O strips receivables	482	503
Liabilities
Time deposits	146,776	158,704
Other deposits	3,749,965	3,246,734
Subordinated Debt.	38,946	40,404
Accrued interest payable	585	707
Carried at fair value \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash and cash equivalents	925,900	457,370
Securities available-for-sale	91,230	120,464
Accrued interest receivable	369	446
Carried at fair value \| Significant Other Observable Inputs (Level 2)
Assets
Securities available-for-sale	232,335	284,361
Securities held-to-maturity	332,452	368,107
Loans (including loans held-for-sale), net	4,324	1,052
Accrued interest receivable	1,778	2,218
I/O strips receivables	482	503
Liabilities
Time deposits	146,776	158,704
Other deposits	3,749,965	3,246,734
Subordinated Debt.	38,946	40,404
Accrued interest payable	585	707
Carried at fair value \| Significant Unobservable Inputs (Level 3)
Assets
Loans (including loans held-for-sale), net	2,631,042	2,512,277
Accrued interest receivable	$ 7,894	$ 8,251

Fair value as of the balance sheet date of accrued interest receivable.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the fair value of deposits other than time deposits as of the balance sheet date.

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Fair value of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required.

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Fair value portion of accrued expenses.

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

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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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Amount of investments classified as other.

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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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