3.	INVESTMENT SECURITIES

The amortized cost, unrealized gains and losses and estimated fair values of investments in debt and other securities at March 31, 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	$	25,444	$	—	$	(219	)	$	25,225
Securities of U.S. government agencies and corporations		35,326		—		(342	)		34,984
Obligations of states and political subdivisions		21,942		137		(181	)		21,898
Collateralized mortgage obligations		67,219		—		(2,338	)		64,881
Mortgage-backed securities		147,983		50		(3,855	)		144,178
Total debt securities	$	297,914	$	187	$	(6,935	)	$	291,166

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 $11,115,000 and $2,737,000 proceeds from sales, calls and maturities of available-for-sale securities for the three months ended March 31, 2018 and March 31, 2017, respectively. There were no gross realized gains from sales/calls of available-for-sale securities for the three months ended March 31, 2018 and March 31, 2017, respectively. There were $0 and $(16,000) gross realized losses from sales/calls of available-for-sale securities for the three months ended March 31, 2018 and March 31, 2017, respectively.

The amortized cost and estimated market value of debt and other securities at March 31, 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	$	27,624	$	27,548
Due after one year through five years		51,047		50,402
Due after five years through ten years		4,041		4,157
Due after ten years		—		—
Subtotal		82,712		82,107
MBS & CMO		215,202		209,059
Total	$	297,914	$	291,166

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 March 31, 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	$	16,811	$	(59	)	$	8,414	$	(160	)	$	25,225	$	(219	)
Securities of U.S. government agencies and corporations		19,960		(119	)		15,024		(223	)		34,984		(342	)
Obligations of states and political subdivisions		5,610		(50	)		7,273		(131	)		12,883		(181	)
Collateralized Mortgage obligations		28,440		(776	)		36,441		(1,562	)		64,881		(2,338	)
Mortgage-backed securities		48,802		(915	)		89,836		(2,940	)		138,638		(3,855	)
Total	$	119,623	$	(1,919	)	$	156,988	$	(5,016	)	$	276,611	$	(6,935	)

No decline in value was considered “other-than-temporary” during the first three months of 2018. Ninety seven securities, all considered investment grade, which had a fair value of $119,623,000 and a total unrealized loss of $1,919,000 have been in an unrealized loss position for less than twelve months as of March 31, 2018. One hundred thirty nine securities, all considered investment grade, which had a fair value of $156,988,000 and a total unrealized loss of $5,016,000 have been in an unrealized loss position for more than twelve months as of March 31, 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 March 31, 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
(in thousands)	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 $32,957,000 and $32,399,000 at March 31, 2018 and December 31, 2017, respectively, were pledged to secure public deposits or for other purposes as required or permitted by law.