Securities

The following tables set forth the amortized cost and estimated fair value of securities available-for-sale and held-to-maturity at the dates indicated.



	At March 31, 2015
(In Thousands)	Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses				Estimated Fair Value
Available-for-sale:
Residential mortgage-backed securities:
GSE (1) issuance REMICs and CMOs (2)	$	294,026		$	5,238		$	(829	)	$	298,435
Non-GSE issuance REMICs and CMOs	4,524			28			(1		)	4,551
GSE pass-through certificates	12,234			594			(2		)	12,826
Total residential mortgage-backed securities	310,784			5,860			(832		)	315,812
Obligations of GSEs	98,681			—			(1,092		)	97,589
Fannie Mae stock	15			—			(13		)	2
Total securities available-for-sale	$	409,480		$	5,860		$	(1,937	)	$	413,403
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	1,490,860		$	20,981		$	(7,138	)	$	1,504,703
Non-GSE issuance REMICs and CMOs	2,299			27			(7		)	2,319
GSE pass-through certificates	271,379			3,431			(1,665		)	273,145
Total residential mortgage-backed securities	1,764,538			24,439			(8,810		)	1,780,167
Multi-family mortgage-backed securities:
GSE issuance REMICs	225,738			2,748			(73		)	228,413
Obligations of GSEs	128,769			536			(476		)	128,829
Other	497			1			—			498
Total securities held-to-maturity	$	2,119,542		$	27,724		$	(9,359	)	$	2,137,907

(1) Government-sponsored enterprise

(2) Real estate mortgage investment conduits and collateralized mortgage obligations



	At December 31, 2014
(In Thousands)	Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses				Estimated Fair Value
Available-for-sale:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	266,946		$	3,608		$	(1,556	)	$	268,998
Non-GSE issuance REMICs and CMOs	5,071			34			(1		)	5,104
GSE pass-through certificates	12,919			640			(2		)	13,557
Total residential mortgage-backed securities	284,936			4,282			(1,559		)	287,659
Obligations of GSEs	98,680			—			(1,982		)	96,698
Fannie Mae stock	15			—			(13		)	2
Total securities available-for-sale	$	383,631		$	4,282		$	(3,554	)	$	384,359
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	1,575,402		$	14,536		$	(14,041	)	$	1,575,897
Non-GSE issuance REMICs and CMOs	2,482			31			(7		)	2,506
GSE pass-through certificates	281,685			2,442			(3,877		)	280,250
Total residential mortgage-backed securities	1,859,569			17,009			(17,925		)	1,858,653
Multi-family mortgage-backed securities:
GSE issuance REMICs	154,381			554			(590		)	154,345
Obligations of GSEs	119,336			42			(1,523		)	117,855
Other	518			—			—			518
Total securities held-to-maturity	$	2,133,804		$	17,605		$	(20,038	)	$	2,131,371

The following tables set forth the estimated fair values of securities with gross unrealized losses at the dates indicated, segregated between securities that have been in a continuous unrealized loss position for less than twelve months and those that have been in a continuous unrealized loss position for twelve months or longer at the dates indicated.



	At March 31, 2015
	Less Than Twelve Months						Twelve Months or Longer						Total
(In Thousands)	Estimated Fair Value		Gross Unrealized Losses				Estimated Fair Value		Gross Unrealized Losses				Estimated Fair Value		Gross Unrealized Losses
Available-for-sale:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	75,161		$	(829	)	$	—		$	—		$	75,161		$	(829	)
Non-GSE issuance REMICs and CMOs	—			—			89			(1		)	89			(1		)
GSE pass-through certificates	86			(1		)	63			(1		)	149			(2		)
Obligations of GSEs	24,857			(125		)	72,732			(967		)	97,589			(1,092		)
Fannie Mae stock	—			—			2			(13		)	2			(13		)
Total temporarily impaired securities available-for-sale	$	100,104		$	(955	)	$	72,886		$	(982	)	$	172,990		$	(1,937	)
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	52,357		$	(294	)	$	339,709		$	(6,844	)	$	392,066		$	(7,138	)
Non-GSE issuance REMICs and CMOs	—			—			294			(7		)	294			(7		)
GSE pass-through certificates	—			—			120,367			(1,665		)	120,367			(1,665		)
Multi-family mortgage-backed securities:
GSE issuance REMICs	25,013			(73		)	—			—			25,013			(73		)
Obligations of GSEs	29,947			(29		)	24,553			(447		)	54,500			(476		)
Total temporarily impaired securities held-to-maturity	$	107,317		$	(396	)	$	484,923		$	(8,963	)	$	592,240		$	(9,359	)



	At December 31, 2014
	Less Than Twelve Months						Twelve Months or Longer						Total
(In Thousands)	Estimated Fair Value		Gross Unrealized Losses				Estimated Fair Value		Gross Unrealized Losses				Estimated Fair Value		Gross Unrealized Losses
Available-for-sale:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	20,587		$	(159	)	$	75,444		$	(1,397	)	$	96,031		$	(1,556	)
Non-GSE issuance REMICs and CMOs	—			—			96			(1		)	96			(1		)
GSE pass-through certificates	53			(1		)	64			(1		)	117			(2		)
Obligations of GSEs	24,586			(395		)	72,112			(1,587		)	96,698			(1,982		)
Fannie Mae stock	—			—			2			(13		)	2			(13		)
Total temporarily impaired securities available-for-sale	$	45,226		$	(555	)	$	147,718		$	(2,999	)	$	192,944		$	(3,554	)
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	121,861		$	(302	)	$	500,348		$	(13,739	)	$	622,209		$	(14,041	)
Non-GSE issuance REMICs and CMOs	—			—			294			(7		)	294			(7		)
GSE pass-through certificates	—			—			164,453			(3,877		)	164,453			(3,877		)
Multi-family mortgage-backed securities:
GSE issuance REMICs	100,355			(590		)	—			—			100,355			(590		)
Obligations of GSEs	—			—			79,413			(1,523		)	79,413			(1,523		)
Total temporarily impaired securities held-to-maturity	$	222,216		$	(892	)	$	744,508		$	(19,146	)	$	966,724		$	(20,038	)

We held 56 securities which had an unrealized loss at March 31, 2015 and 80 securities which had an unrealized loss at December 31, 2014. At March 31, 2015 and December 31, 2014, substantially all of the securities in an unrealized loss position had a fixed interest rate and the cause of the temporary impairment was directly related to changes in interest rates. We generally view changes in fair value caused by changes in interest rates as temporary, which is consistent with our experience. None of the unrealized losses are related to credit losses. Therefore, at March 31, 2015 and December 31, 2014, the impairments were deemed temporary based on (1) the direct relationship of the decline in fair value to movements in interest rates, (2) the estimated remaining life and high credit quality of the investments and (3) the fact that we had no intention to sell these securities and it was not more likely than not that we would be required to sell these securities before their anticipated recovery of the remaining amortized cost basis and we expected to recover the entire amortized cost basis of the security.

At March 31, 2015, available-for-sale debt securities, excluding mortgage-backed securities, had an amortized cost of $98.7 million, an estimated fair value of $97.6 million and contractual maturities in 2021 and 2022. At March 31, 2015, held-to-maturity debt securities, excluding mortgage-backed securities, had an amortized cost and an estimated fair value of $129.3 million and contractual maturities primarily in 2021 and 2023. Actual maturities may differ from contractual maturities because issuers may have the right to prepay or call obligations with or without prepayment penalties.

At March 31, 2015, the amortized cost of callable securities in our portfolio totaled $227.4 million, of which $211.0 million are callable within one year and at various times thereafter.

The balance of accrued interest receivable for securities totaled $6.7 million at March 31, 2015 and December 31, 2014.