Note 2 - Investments Securities Available-for-Sale

The following summarizes the amortized cost of investment securities classified as available-for-sale and their approximate fair values at March 31, 2019 and December 31, 2018:

The scheduled maturities of debt securities were as follows at March 31, 2019. Actual maturities of mortgage-backed securities may differ from contractual maturities because the mortgages underlying the securities may be repaid without any penalties. Because mortgage-backed securities are not due at a single maturity date, they are not included in the maturity categories in the following maturity summary.

During the three months ended March 31, 2019, gross realized gains on sales and calls were $216,000, and gross losses realized were $103,000. There were no realized gains or losses on sales and calls during the three months ended March 31, 2018.

There were no securities of issuers whose aggregate carrying amount exceeded 10% of equity at March 31, 2019.

Securities with carrying amounts of $38.1 million and $31.1 million were pledged to secure available borrowings with the Federal Reserve Bank and Federal Home Loan Bank at March 31, 2019 and December 31, 2018, respectively.

The aggregate fair value and unrealized losses of securities that have been in a continuous unrealized-loss position for less than twelve months and for twelve months or more, and are temporarily impaired, are as follows at March 31, 2019 and December 31, 2018:

Government mortgage-backed securities, state and municipal securities and asset-backed securities: Because the decline in fair value of the government mortgage-backed securities, asset-backed securities and state and municipal securities is primarily attributable to changes in market interest rates and not credit quality, and because the Company has the intent and ability to hold these investments until market price recovery or maturity, these investments are not considered other-than-temporarily impaired.

Note 3 - Investments Securities Available-for-Sale

The following summarizes the amortized cost of investment securities classified as available-for-sale and their approximate fair values at December 31, 2018 and 2017:

The scheduled maturities of debt securities were as follows at December 31, 2018. Actual maturities of mortgage-backed securities may differ from contractual maturities because the mortgages underlying the securities may be repaid without any penalties. Because mortgage-backed securities are not due at a single maturity date, they are not included in the maturity categories in the following maturity summary.

There were no realized gains or losses on sales and calls during the year ended December 31, 2018. During the year ended December 31, 2017, gross realized gains on sales and calls were $6.4 million, and gross losses realized were $505,000.

There were no securities of issuers whose aggregate carrying amount exceeded 10% of equity at December 31, 2018.

Securities with carrying amounts of $31.1 million and $39.8 million were pledged to secure available borrowings with the Federal Reserve Bank and Federal Home Loan Bank at December 31, 2018 and 2017, respectively.

The aggregate fair value and unrealized losses of securities that have been in a continuous unrealized-loss position for less than twelve months and for twelve months or more, and are temporarily impaired, are as follows at December 31, 2018 and 2017:

Government mortgage-backed securities, state and municipal securities and asset-backed securities: Because the decline in fair value of the government mortgage-backed securities, asset-backed securities and state and municipal securities is primarily attributable to changes in market interest rates and not credit quality, and because the Company has the intent and ability to hold these investments until market price recovery or maturity, these investments are not considered other-than-temporarily impaired.