rtized cost and fair value of securities available-for-sale at December 31, 2017 and 2016 are summarized as follow (in thousands):



	December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Government-sponsored enterprises (GSEs)	$	26,207	$	1	$	(432	)	$	25,776
Municipal securities	9,122		28		(147		)	9,003
Other debt securities	974		—		(24		)	950
Mortgage-backed securities	117,263		136		(1,184		)	116,215
Total	$	153,566	$	165	$	(1,787	)	$	151,944



	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Government-sponsored enterprises (GSEs)	$	18,279	$	8	$	(564	)	$	17,723
Municipal securities	8,182		16		(179		)	8,019
Mortgage-backed securities	104,585		185		(1,090		)	103,680
Total	$	131,046	$	209	$	(1,833	)	$	129,422

The amortized cost and estimated market value of securities at December 31, 2017, by contractual maturity, are shown below (in thousands). 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.



	Amortized Cost		Fair Value
Due in one year or less	$	2,174	$	2,175
Due from one year to five years	21,606		21,292
Due from five years to ten years	8,037		7,822
Due after ten years	4,486		4,440
	36,303		35,729
Mortgage-backed securities	117,263		116,215
Total	$	153,566	$	151,944

The following tables present the gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities available-for-sale have been in a continuous unrealized loss position, as of December 31, 2017 and 2016 (in thousands):



	As of December 31, 2017
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. Government- sponsored enterprises (GSEs)	$	1,358	$	(1	)	$	13,420	$	(431	)	$	14,778	$	(432	)
Municipal securities	3,418		(43		)	2,112		(104		)	5,530		(147		)
Other debt securities	950		(24		)	—		—			950		(24		)
Mortgage-backed securities	61,332		(407		)	35,048		(777		)	96,380		(1,184		)
Total	$	67,058	$	(475	)	$	50,580	$	(1,312	)	$	117,638	$	(1,787	)



	As of December 31, 2016
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. Government- sponsored enterprises (GSEs)	$	14,702	$	(564	)	$	—	$	—		$	14,702	$	(564	)
Municipal securities	6,368		(179		)	—		—			6,368		(179		)
Mortgage-backed securities	67,063		(690		)	8,948		(400		)	76,011		(1,090		)
Total	$	88,133	$	(1,433	)	$	8,948	$	(400	)	$	97,081	$	(1,833	)

At December 31, 2017, the categories of temporarily impaired securities, and management’s evaluation of those securities, are as follows:

U.S. Government-sponsored enterprises: At December 31, 2017, six investments in U.S. GSE securities had unrealized losses. These unrealized losses related principally to changes in market interest rates. The contractual terms of the investments does not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. Because the Bank does not intend to sell the investments and it is more likely than not that the Bank will not be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Bank does not consider these investments to be other-than temporarily impaired at December 31, 2017.

Municipal securities: At December 31, 2017, thirteen investments in obligations of municipal securities had unrealized losses. The Bank believes the unrealized losses on those investments were caused by the interest rate environment and do not relate to the underlying credit quality of the issuers. Because the Bank does not intend to sell the investments and it is not more likely than not that the Bank will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Bank does not consider these investments to be other than temporarily impaired at December 31, 2017.

Other debt securities: At December 31, 2017, one investment in other debt securities had unrealized losses. The Bank believes the unrealized losses on this investment was caused by the interest rate environment and does not relate to the underlying credit quality of the issuers. Because the Bank does not intend to sell the investment and it is not more likely than not that the Bank will be required to sell the investment before recovery of their amortized cost bases, which may be maturity, the Bank does not consider this investment to be other than temporarily impaired at December 31, 2017.

Mortgage-backed securities: At December 31, 2017, sixty investments in residential mortgage-backed securities had unrealized losses. This impairment is believed to be caused by the current interest rate environment. The contractual cash flows of those investments are guaranteed by an agency of the U.S. Government. Because the decline in market value is attributable to the current interest rate environment and not credit quality, and because the Bank does not intend to sell the investments and it is not more likely than not that the Bank will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, the Bank does not consider these investments to be other than temporarily impaired at December 31, 2017.

Sales of available for sale securities for the years ended December 31, 2017 and 2016, were as follows (in thousands):



	2017		2016
Proceeds	$	12,614	$	31,599
Gains realized	145		200
Losses realized	2		—

Securities with a carrying value of $97,160,059 and $86,351,097 at December 31, 2017 and 2016, respectively, were pledged to secure various deposits, securities sold under agreements to repurchase, as collateral for federal funds purchased from other financial institutions and serve as collateral for borrowings at the Federal Home Loan Bank.