The amortized cost, gross unrealized gains, gross unrealized losses, and approximate fair value of securities available for sale consisted of the following:

	March 31, 2018
		Gross	Gross	Estimated
	Amortized	Unrealized	Unrealized	Fair
(dollars in thousands)	Cost	Gains	Losses	Value

Investment and mortgage backed securities:
U.S. government-sponsored enterprises (GSEs)	$11,504	$-	$(120)	$11,384
State and political subdivisions	51,457	395	(555)	51,297
Other securities	5,291	76	(235)	5,132
Mortgage-backed: GSE residential	80,313	1	(2,000)	78,314
Total investments and mortgage-backed securities	$148,565	$472	$(2,910)	$146,127

	June 30, 2017
		Gross	Gross	Estimated
	Amortized	Unrealized	Unrealized	Fair
(dollars in thousands)	Cost	Gains	Losses	Value

Investment and mortgage backed securities:
U.S. government-sponsored enterprises (GSEs)	$10,433	$17	$(12)	$10,438
State and political subdivisions	49,059	1,046	(127)	49,978
Other securities	6,017	306	(598)	5,725
Mortgage-backed GSE residential	78,088	490	(303)	78,275
Total investments and mortgage-backed securities	$143,597	$1,859	$(1,040)	$144,416

The amortized cost and estimated fair value of investment and mortgage-backed securities, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalties.

	March 31, 2018
	Amortized	Estimated
(dollars in thousands)	Cost	Fair Value
Within one year	$4,762	$4,759
After one year but less than five years	20,065	19,944
After five years but less than ten years	23,277	23,243
After ten years	20,148	19,867
Total investment securities	68,252	67,813
Mortgage-backed securities	80,313	78,314
Total investments and mortgage-backed securities	$148,565	$146,127

The carrying value of investment and mortgage-backed securities pledged as collateral to secure public deposits and securities sold under agreements to repurchase amounted to $116.1 million at March 31, 2018 and $114.1 million at June 30, 2017. The securities pledged consist of marketable securities, including $7.4 million and $6.5 million of U.S. Government and Federal Agency Obligations, $40.8 million and $50.5 million of Mortgage-Backed Securities, $28.3 million and $19.9 million of Collateralized Mortgage Obligations, $39.2 million and $36.8 million of State and Political Subdivisions Obligations, and $400,000 and $400,000 of Other Securities at March 31, 2018 and June 30, 2017, respectively.

Gains of $344,391 and $395,843 were recognized from sales of available-for-sale securities in the three- and nine- month periods ended March 31, 2018. Losses of $89,996 and $104,341 were recognized from sales of available-for-sale securities in the three- and nine- month periods ended March 31, 2018. There were no sales of available-for-sale securities in the three- and nine- month periods ended March 31, 2017.

The following tables show our investments’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2018 and June 30, 2017:

	March 31, 2018
	Less than 12 months		12 months or more		Total
		Unrealized		Unrealized		Unrealized
	Fair Value	Losses	Fair Value	Losses	Fair Value	Losses
(dollars in thousands)
U.S. government-sponsored enterprises (GSEs)	$7,943	$65	$2,443	$55	$10,386	$120
Obligations of state and political subdivisions	19,157	292	8,215	263	27,372	555
Other securities	985	7	1,069	228	2,054	235
Mortgage-backed securities	57,193	1,185	21,015	815	78,208	2,000
Total investments and mortgage-backed securities	$85,278	$1,549	$32,742	$1,361	$118,020	$2,910

	June 30, 2017
	Less than 12 months		12 months or more		Total
		Unrealized		Unrealized		Unrealized
	Fair Value	Losses	Fair Value	Losses	Fair Value	Losses
(dollars in thousands)
U.S. government-sponsored enterprises (GSEs)	$6,457	$12	$-	$-	$6,457	$12
Obligations of state and political subdivisions	12,341	127	256	-	12,597	127
Other securities	-	-	1,160	598	1,160	598
Mortgage-backed securities	29,836	267	2,285	36	32,121	303
Total investments and mortgage-backed securities	$48,634	$406	$3,701	$634	$52,335	$1,040

Other securities. At March 31, 2018, there were 2 pooled trust preferred securities with an estimated fair value of $750,000 and unrealized losses of $221,000 in a continuous unrealized loss position for twelve months or more. These unrealized losses were primarily due to the long-term nature of the pooled trust preferred securities and a reduced demand for these securities, and concerns regarding the financial institutions that issued the underlying trust preferred securities. Rules adopted by the federal banking agencies in December 2013 to implement Section 619 of the Dodd-Frank Act (the “Volcker Rule”) generally prohibit banking entities from engaging in proprietary trading and from investing in, sponsoring, or having certain relationships with a hedge fund or private equity fund. The pooled trust preferred securities owned by the Company were included in a January 2014 listing of securities which the agencies considered to be grandfathered with regard to these prohibitions; as such, banking entities are permitted to retain their interest in these securities, provided the interest was acquired on or before December 10, 2013, unless acquired pursuant to a merger or acquisition.

The March 31, 2018, cash flow analysis for these two securities indicated it is probable the Company will receive all contracted principal and related interest projected. The cash flow analysis used in making this determination was based on anticipated default, recovery, and prepayment rates, and the resulting cash flows were discounted based on the yield spread anticipated at the time the securities were purchased. Other inputs include the actual collateral attributes, which include credit ratings and other performance indicators of the underlying financial institutions, including profitability, capital ratios, and asset quality. Assumptions for these two securities included annualized prepayments of 1.4 to 1.6 percent; no recoveries on currently deferred issuers; new deferrals of 40 to 50 basis points annually; and eventual recoveries of nine percent of new deferrals.

One of these two securities has continued to receive cash interest payments in full since our purchase; the other security received principal-in-kind (PIK), in lieu of cash interest, for a period of time following the recession and financial crisis which began in 2008, but resumed cash interest payments during fiscal 2014. Our cash flow analysis indicates that cash interest payments are expected to continue for the securities. Because the Company does not intend to sell these securities and it is not more-likely-than-not that the Company will be required to sell these securities prior to recovery of their amortized cost basis, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired at March 31, 2018.

The Company does not believe any other individual unrealized loss as of March 31, 2018, represents OTTI. However, the Company could be required to recognize OTTI losses in future periods with respect to its available for sale investment securities portfolio. The amount and timing of any additional OTTI will depend on the decline in the underlying cash flows of the securities. Should the impairment of any of these securities become other-than-temporary, the cost basis of the investment will be reduced and the resulting loss recognized in the period the other-than-temporary impairment is identified.

Credit losses recognized on investments. As described above, one of the Company’s investments in trust preferred securities experienced fair value deterioration due to credit losses, but is not otherwise other-than-temporarily impaired. During fiscal 2009, the Company adopted ASC 820, formerly FASB Staff Position 157-4, “Determining Fair Value When the Volume and Level of Activity for the Asset or Liability Have Significantly Decreased and Identifying Transactions That Are Not Orderly.” The following table provides information about the trust preferred security for which only a credit loss was recognized in income and other losses are recorded in other comprehensive income (loss) for the nine-month periods ended March 31, 2018 and 2017.

	Accumulated Credit Losses
	Nine-Month Period Ended
(dollars in thousands)	March 31,
	2018	2017
Credit losses on debt securities held
Beginning of period	$340	$352
Additions related to OTTI losses not previously recognized	-	-
Reductions due to sales	(333)	-
Reductions due to change in intent or likelihood of sale	-	-
Additions related to increases in previously-recognized OTTI losses	-	-
Reductions due to increases in expected cash flows	(7)	(9)
End of period	$-	$343