Securities

The amortized cost and estimated fair value of investments in securities at December 31, 2017 and 2016 were as follows (dollars in thousands):



	December 31, 2017
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Securities available for sale:
Federal agencies and GSEs	$	114,246	$	8	$	2,127	$	112,127
Mortgage-backed and CMOs	106,163		293		1,140		105,316
State and municipal	92,711		1,262		347		93,626
Corporate	7,842		234		14		8,062
Equity securities	1,383		823		—		2,206
Total securities available for sale	$	322,345	$	2,620	$	3,628	$	321,337



	December 31, 2016
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Securities available for sale:
Federal agencies and GSEs	$	106,379	$	62	$	2,387	$	104,054
Mortgage-backed and CMOs	79,917		514		938		79,493
State and municipal	145,757		2,540		782		147,515
Corporate	13,392		123		23		13,492
Equity securities	1,288		660		—		1,948
Total securities available for sale	$	346,733	$	3,899	$	4,130	$	346,502

The amortized cost and estimated fair value of investments in securities at December 31, 2017, by contractual maturity, are shown in the following table. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Because mortgage-backed securities have both known principal repayment terms as well as unknown principal repayments due to potential borrower pre-payments, it is difficult to accurately predict the final maturity of these investments. Mortgage-backed securities are shown separately (dollars in thousands):



	Available for Sale
	Amortized Cost		Fair Value
Due in one year or less	$	11,540	$	11,549
Due after one year through five years	102,806		102,982
Due after five years through ten years	73,884		73,072
Due after ten years	26,569		26,212
Mortgage-backed and CMOs	106,163		105,316
Equity securities	1,383		2,206
	$	322,345	$	321,337

Gross realized gains and losses from the sale of securities available for sale were as follows (dollars in thousands):



	For the Years Ended December 31,
	2017			2016			2015
Realized gains	$	825		$	844		$	871
Realized losses	(13		)	(8		)	(4		)
Other-than-temporary impairment	—			—			—

Securities with a carrying value of approximately $166,284,000 and $202,577,000 at December 31, 2017 and 2016, respectively, were pledged to secure public deposits, repurchase agreements, and for other purposes as required by law. FHLB letters of credit were used as additional collateral in the amounts of $190,700,000 at December 31, 2017 and $130,700,000 at December 31, 2016.

Temporarily Impaired Securities

The following table shows estimated fair value and gross unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2017. The reference point for determining when securities are in an unrealized loss position is month-end. Therefore, it is possible that a security's market value exceeded its amortized cost on other days during the past twelve-month period.

Available for sale securities that have been in a continuous unrealized loss position are as follows (dollars in thousands):



	Total				Less than 12 Months				12 Months or More
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Federal agencies and GSEs	$	99,133	$	2,127	$	45,474	$	321	$	53,659	$	1,806
Mortgage-backed and CMOs	90,806		1,140		64,449		533		26,357		607
State and municipal	34,550		347		27,442		159		7,108		188
Corporate	1,529		14		495		5		1,034		9
Total	$	226,018	$	3,628	$	137,860	$	1,018	$	88,158	$	2,610

Federal agencies and GSEs: The unrealized losses on the Company's investment in 24 government sponsored entities ("GSE") were caused by interest rate increases. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. Because the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017.

Mortgage-backed securities: The unrealized losses on the Company's investment in 53 GSE mortgage-backed securities were caused by interest rate increases. Sixteen of these securities were in an unrealized loss position for 12 months or more. The contractual cash flows of those investments are guaranteed by an agency of the U.S. Government. Accordingly, it is expected that the securities would not be settled at a price less than the amortized cost bases of the Company's investments. Because the decline in market value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017.

Collateralized Mortgage Obligations: The unrealized loss associated with one private GSE collateralized mortgage obligation ("CMO") is due to normal market fluctuations. This security has been in an unrealized loss position for 12 months or more. The contractual cash flows of those investments are guaranteed by an agency of the U.S. Government. Accordingly, it is expected that the securities would not be settled at a price less than the amortized cost bases of the Company's investments. Because the decline in market value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017.

State and municipal securities: The unrealized losses on 50 state and municipal securities were caused by interest rate increases and not credit deterioration. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. Because the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017.

Corporate securities: The unrealized losses on two corporate securities were caused by interest rate increases and not credit deterioration. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. Because the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Company does not consider those investments to be other-than-temporarily impaired at December 31, 2017.

Due to restrictions placed upon the Bank's common stock investment in the Federal Reserve Bank of Richmond and FHLB, these securities have been classified as restricted equity securities and carried at cost. These restricted securities are not subject to the investment security classifications and are included as a separate line item on the Company's Consolidated Balance Sheet. The FHLB requires the Bank to maintain stock in an amount equal to 4.25% of outstanding borrowings and a specific percentage of the Bank's total assets. The Federal Reserve Bank of Richmond requires the Bank to maintain stock with a par value equal to 3.0% of its outstanding capital and an additional 3.0% is on call. Restricted equity securities consist of Federal Reserve Bank of Richmond stock in the amount of $3,587,000 and $3,559,000 as of December 31, 2017 and 2016 and FHLB stock in the amount of $2,523,000 and $2,665,000 as of December 31, 2017 and 2016, respectively.

The table below shows gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities had been in a continuous unrealized loss position, at December 31, 2016 (dollars in thousands):



	Total				Less than 12 Months				12 Months or More
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Federal agencies and GSEs	$	89,597	$	2,387	$	89,597	$	2,387	$	—	$	—
Mortgage-backed and CMOs	57,762		938		56,076		911		1,686		27
State and municipal	47,221		782		47,221		782		—		—
Corporate	2,895		23		2,895		23		—		—
Total	$	197,475	$	4,130	$	195,789	$	4,103	$	1,686	$	27

Other-Than-Temporary-Impaired Securities

As of December 31, 2017 and 2016, there were no securities classified as other-than-temporary impaired.