3. INVESTMENT SECURITIES

The amortized cost, unrealized gains and losses and estimated fair values of investments in debt and other securities at June 30, 2018 are summarized as follows:

(in thousands)	Amortized cost		Unrealized gains		Unrealized losses			Estimated fair value

Investment securities available-for-sale:
U.S. Treasury Securities	$	30,433	$	—	$	(242	)	$	30,191
Securities of U.S. government agencies and corporations		38,318		—		(360	)		37,958
Obligations of states and political subdivisions		18,414		124		(167	)		18,371
Collateralized mortgage obligations		66,296		—		(2,659	)		63,637
Mortgage-backed securities		140,052		33		(4,333	)		135,752

Total debt securities	$	293,513	$	157	$	(7,761	)	$	285,909

The amortized cost, unrealized gains and losses and estimated fair values of investments in debt and other securities at December 31, 2017 are summarized as follows:

(in thousands)	Amortized cost		Unrealized gains		Unrealized losses			Estimated fair value

Investment securities available-for-sale:
U.S. Treasury Securities	$	18,589	$	—	$	(125	)	$	18,464
Securities of U.S. government agencies and corporations		21,353		—		(244	)		21,109
Obligations of states and political subdivisions		23,138		216		(146	)		23,208
Collateralized mortgage obligations		67,724		—		(1,641	)		66,083
Mortgage-backed securities		154,143		95		(2,361	)		151,877

Total debt securities	$	284,947	$	311	$	(4,517	)	$	280,741

The Company had $3,465,000 and $14,580,000 in proceeds from sales, calls and maturities of available-for-sale securities for the three and six months ended June 30, 2018, respectively. The Company had $0 and $2,737,000 in proceeds from sales, calls and maturities of available-for-sale securities for the three and six months ended June 30, 2017, respectively. There were no gross realized gains on sales of available-for-sale securities for the three and six months ended June 30, 2018 and June 30, 2017. There were no gross realized losses from sales of available-for-sale securities for the three and six months ended June 30, 2018. Gross realized losses from sales of available-for-sale securities were $0 and $(16,000) for the three and six months ended June 30, 2017, respectively.

The amortized cost and estimated market value of debt and other securities at June 30, 2018, by contractual and expected maturity, are shown in the following table:

(in thousands)	Amortized cost		Estimated fair value

Maturity in years:
Due in one year or less	$	36,120	$	36,000
Due after one year through five years		47,010		46,380
Due after five years through ten years		4,035		4,140
Subtotal		87,165		86,520
MBS & CMO		206,348		199,389
Total	$	293,513	$	285,909

Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. In addition, factors such as prepayments and interest rates may affect the yield on the carrying value of mortgage-related securities.

An analysis of gross unrealized losses of the available-for-sale investment securities portfolio as of June 30, 2018, follows:

	Less than 12 months					12 months or more					Total
(in thousands)	Fair Value		Unrealized losses			Fair Value		Unrealized losses			Fair Value		Unrealized losses

U.S. Treasury securities	$	21,788	$	(80	)	$	8,403	$	(162	)	$	30,191	$	(242	)
Securities of U.S. government agencies and corporations		20,841		(132	)		17,117		(228	)		37,958		(360	)
Obligations of states and political subdivisions		6,179		(54	)		6,075		(113	)		12,254		(167	)
Collateralized mortgage obligations		19,502		(576	)		44,135		(2,083	)		63,637		(2,659	)
Mortgage-backed securities		45,840		(1,120	)		84,797		(3,213	)		130,637		(4,333	)

Total	$	114,150	$	(1,962	)	$	160,527	$	(5,799	)	$	274,677	$	(7,761	)

No decline in value was considered "other-than-temporary" during the first six months of 2018. One hundred two securities, all considered investment grade, which had a fair value of $114,150,000 and a total unrealized loss of $1,962,000, have been in an unrealized loss position for less than twelve months as of June 30, 2018. One hundred forty-five securities, all considered investment grade, which had a fair value of $160,527,000 and a total unrealized loss of $5,799,000, have been in an unrealized loss position for more than twelve months as of June 30, 2018. The unrealized losses on the Company's investment securities were caused by market conditions for these types of investments, particularly changes in risk-free interest rates. The Company does not intend to sell the securities and has concluded it is not more likely than not that we will be required to sell these securities prior to recovery of their anticipated cost basis. Therefore, the Company does not consider these investments to be other than temporarily impaired as of June 30, 2018.

The fair value of investment securities could decline in the future if the general economy deteriorates, inflation increases, credit ratings decline, the issuer's financial condition deteriorates, or the liquidity for securities declines. As a result, other than temporary impairments may occur in the future.

An analysis of gross unrealized losses of the available-for-sale investment securities portfolio as of December 31, 2017, follows:


	Less than 12 months							12 months or more							Total
	Fair Value			Unrealized losses				Fair Value			Unrealized losses				Fair Value			Unrealized losses

U.S. Treasury Securities		$	10,004		$	(2	)		$	8,460		$	(123	)		$	18,464		$	(125	)
Securities of U.S. government agencies and corporations			6,049			(50	)			15,060			(194	)			21,109			(244	)
Obligations of states and political subdivisions			7,677			(34	)			7,116			(112	)			14,793			(146	)
Collateralized mortgage obligations			31,679			(576	)			34,404			(1,065	)			66,083			(1,641	)
Mortgage-backed securities			62,320			(650	)			76,478			(1,711	)			138,798			(2,361	)

Total		$	117,729		$	(1,312	)		$	141,518		$	(3,205	)		$	259,247		$	(4,517	)

Investment securities carried at $36,084,000 and $32,399,000 at June 30, 2018 and December 31, 2017, respectively, were pledged to secure public deposits or for other purposes as required or permitted by law.