6. BORROWINGS

Short-term Borrowings

The Company classifies all borrowings that will mature within a year from the date on which the Company enters into them as short-term borrowings. Total short-term borrowings consist primarily of advances from the FHLB, federal funds purchased (which are secured overnight borrowings from other financial institutions), and other lines of credit. Also included in total short-term borrowings are securities sold under agreements to repurchase, which are secured transactions with customers and generally mature the day following the date sold.

Total short-term borrowings consist of the following as of September 30, 2021 and December 31, 2020 (dollars in thousands):

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The Bank maintains federal funds lines with several correspondent banks, the remaining available balance was $997.0 million and $847.0 million at September 30, 2021 and December 31, 2020, respectively. The Company maintains an alternate line of credit at a correspondent bank, which had an available balance of $25.0 million at both September 30, 2021 and December 31, 2020. The Company has certain restrictive covenants related to certain asset quality, capital, and profitability metrics associated with these lines and is in compliance with such covenants as of September 30, 2021 and December 31, 2020. Additionally, the Company had a collateral dependent line of credit with the FHLB of up to $6.0 billion at both September 30, 2021 and December 31, 2020.

Long-term Borrowings

In response to the current interest rate environment, the Company prepaid a $200.0 million long-term FHLB advance on February 26, 2021 and $550.0 million of long-term FHLB advances in 2020, which resulted in prepayment penalties of $14.7 million and $31.2 million, respectively.

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Total long-term borrowings consist of the following as of September 30, 2021 (dollars in thousands):

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⁽¹⁾ Rate as of September 30, 2021.

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⁽²⁾ The total of the trust preferred capital securities and investments in the respective trusts represents the principal asset of the Company’s junior subordinated debt securities with like maturities and like interest rates to the capital securities. The Company’s investment in the trusts is reported in "Other Assets" on the Company’s Consolidated Balance Sheets.

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⁽³⁾ The remaining issuance discount as of September 30, 2021 is $1.0 million.

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⁽⁴⁾ Subordinated notes qualify as Tier 2 capital for the Company for regulatory purposes.

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⁽⁵⁾ Fixed-to-floating rate notes are redeemable, at the Company’s option, on any interest payment date occurring on or after December 15, 2021, at which time the interest rate will change to a floating rate of LIBOR plus 3.175% through its maturity date or earlier redemption.

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⁽⁶⁾ Includes discount on issued subordinated notes.

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Total long-term borrowings consist of the following as of December 31, 2020 (dollars in thousands):

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⁽¹⁾ Rate as of December 31, 2020.

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⁽²⁾ The total of the trust preferred capital securities and investments in the respective trusts represents the principal asset of the Company’s junior subordinated debt securities with like maturities and like interest rates to the capital securities. The Company’s investment in the trusts is reported in "Other Assets" on the Company’s Consolidated Balance Sheets.

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⁽³⁾ The remaining issuance discount as of December 31, 2020 is $1.2 million.

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⁽⁴⁾ Subordinated notes qualify as Tier 2 capital for the Company for regulatory purposes.

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⁽⁵⁾ Fixed-to-floating rate notes are redeemable, at the Company’s option, on any interest payment date occurring on or after December 15, 2021, at which time the interest rate will change to a floating rate of LIBOR plus 3.175% through its maturity date or earlier redemption.

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⁽⁶⁾ Includes discount on issued subordinated notes.

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As of September 30, 2021, the contractual maturities of long-term debt are as follows for the years ending (dollars in thousands):

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⁽¹⁾ Includes discount on issued subordinated notes.