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, 2016
(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)	$	297,400		$	4,846		$	(459	)	$	301,787
Non-GSE issuance REMICs and CMOs	2,612			7			(2		)	2,617
GSE pass-through certificates	10,292			454			(2		)	10,744
Total residential mortgage-backed securities	310,304			5,307			(463		)	315,148
Obligations of GSEs	73,701			28			—			73,729
Fannie Mae stock	15			—			(14		)	1
Total securities available-for-sale	$	384,020		$	5,335		$	(477	)	$	388,878
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	1,305,818		$	20,083		$	(3,049	)	$	1,322,852
Non-GSE issuance REMICs and CMOs	197			—			(7		)	190
GSE pass-through certificates	250,658			3,420			(881		)	253,197
Total residential mortgage-backed securities	1,556,673			23,503			(3,937		)	1,576,239
Multi-family mortgage-backed securities:
GSE issuance REMICs	613,877			8,381			(171		)	622,087
Obligations of GSEs	192,541			483			(87		)	192,937
Corporate Debt securities	80,000			214			(2,432		)	77,782
Other	412			1			—			413
Total securities held-to-maturity	$	2,443,503		$	32,582		$	(6,627	)	$	2,469,458


(1)	Government-sponsored enterprise


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



	At December 31, 2015
(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	$	331,099		$	2,374		$	(2,934	)	$	330,539
Non-GSE issuance REMICs and CMOs	3,048			13			(7		)	3,054
GSE pass-through certificates	10,781			485			(2		)	11,264
Total residential mortgage-backed securities	344,928			2,872			(2,943		)	344,857
Obligations of GSEs	73,701			—			(1,762		)	71,939
Fannie Mae stock	15			—			(13		)	2
Total securities available-for-sale	$	418,644		$	2,872		$	(4,718	)	$	416,798
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	1,361,907		$	8,135		$	(14,128	)	$	1,355,914
Non-GSE issuance REMICs and CMOs	198			—			(5		)	193
GSE pass-through certificates	260,707			1,535			(3,413		)	258,829
Total residential mortgage-backed securities	1,622,812			9,670			(17,546		)	1,614,936
Multi-family mortgage-backed securities:
GSE issuance REMICs	434,587			1,255			(2,334		)	433,508
Obligations of GSEs	178,967			220			(480		)	178,707
Corporate debt securities	60,000			—			(1,493		)	58,507
Other	433			1			—			434
Total securities held-to-maturity	$	2,296,799		$	11,146		$	(21,853	)	$	2,286,092

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, 2016
	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	$	19,950		$	(131	)	$	23,962		$	(328	)	$	43,912		$	(459	)
Non-GSE issuance REMICs and CMOs	109			(1		)	63			(1		)	172			(2		)
GSE pass-through certificates	16			(1		)	99			(1		)	115			(2		)
Fannie Mae stock	—			—			1			(14		)	1			(14		)
Total temporarily impaired securities available-for-sale	$	20,075		$	(133	)	$	24,125		$	(344	)	$	44,200		$	(477	)
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	51,103		$	(149	)	$	234,606		$	(2,900	)	$	285,709		$	(3,049	)
Non-GSE issuance REMICs and CMOs	—			—			190			(7		)	190			(7		)
GSE pass-through certificates	—			—			104,675			(881		)	104,675			(881		)
Multi-family mortgage-backed securities:
GSE issuance REMICs	79,344			(171		)	—			—			79,344			(171		)
Obligations of GSEs	24,888			(87		)	—			—			24,888			(87		)
Corporate debt securities	67,569			(2,432		)	—			—			67,569			(2,432		)
Total temporarily impaired securities held-to-maturity	$	222,904		$	(2,839	)	$	339,471		$	(3,788	)	$	562,375		$	(6,627	)



	At December 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	$	189,364		$	(2,934	)	$	—		$	—		$	189,364		$	(2,934	)
Non-GSE issuance REMICs and CMOs	75			(2		)	64			(5		)	139			(7		)
GSE pass-through certificates	97			(1		)	103			(1		)	200			(2		)
Obligations of GSEs	24,602			(390		)	47,337			(1,372		)	71,939			(1,762		)
Fannie Mae stock	—			—			2			(13		)	2			(13		)
Total temporarily impaired securities available-for-sale	$	214,138		$	(3,327	)	$	47,506		$	(1,391	)	$	261,644		$	(4,718	)
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	395,659		$	(3,972	)	$	289,645		$	(10,156	)	$	685,304		$	(14,128	)
Non-GSE issuance REMICs and CMOs	—			—			193			(5		)	193			(5		)
GSE pass-through certificates	56,503			(586		)	106,738			(2,827		)	163,241			(3,413		)
Multi-family mortgage-backed securities:
GSE issuance REMICs	276,601			(2,334		)	—			—			276,601			(2,334		)
Obligations of GSEs	107,824			(480		)	—			—			107,824			(480		)
Corporate debt securities	58,507			(1,493		)	—			—			58,507			(1,493		)
Total temporarily impaired securities held-to-maturity	$	895,094		$	(8,865	)	$	396,576		$	(12,988	)	$	1,291,670		$	(21,853	)

We held 61 securities which had an unrealized loss at March 31, 2016 and 129 securities which had an unrealized loss at December 31, 2015. Securities in unrealized loss positions are analyzed as part of our ongoing assessment of other-than-temporary impairment. Our assertion regarding our intent not to sell, or that it is not more likely than not that we will be required to sell a security before its anticipated recovery, is based on a number of factors, including a quantitative estimate of the expected recovery period (which may extend to maturity), and our intended strategy with respect to the identified security or portfolio. If we do have the intent to sell, or believe it is more likely than not that we will be required to sell the security before its anticipated recovery, the unrealized loss is charged directly to earnings in the Consolidated Statements of Income and Comprehensive Income. Other factors considered in determining whether or not an impairment is temporary include the severity of the impairment; the duration of the impairment; the cause of the impairment; the near-term prospects of the issuer; and the estimated recovery period. The unrealized losses on our residential and multi-family mortgage-backed securities and GSE obligations at March 31, 2016 were primarily caused by movements in market interest rates subsequent to the purchase of such securities or obligations. The unrealized losses on our corporate debt obligations was primarily due to the observed credit spread widening that occurred during the first quarter of 2016, which we attribute to the contemporaneous broad-based equity market volatility. We do not consider the resulting unrealized losses to be anything other than temporary impairment.

During the three months ended March 31, 2016, proceeds from sales of securities from the available-for-sale portfolio totaled $23.1 million, resulting in gross realized gains of $86,000. There were no sales of securities from the available-for-sale portfolio during the three months ended March 31, 2015.

At March 31, 2016, available-for-sale debt securities, excluding mortgage-backed securities, had an amortized cost of $73.7 million, an estimated fair value of $73.7 million and contractual maturities in 2021 and 2022. At March 31, 2016, held-to-maturity debt securities, excluding mortgage-backed securities, had an amortized cost of $273.0 million, an estimated fair value of $271.1 million and contractual maturities primarily in 2016 through 2027. 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, 2016, the amortized cost of callable securities in our portfolio totaled $211.3 million, of which $194.9 million are callable within one year and at various times thereafter. The balance of accrued interest receivable for securities totaled $7.2 million at March 31, 2016 and $7.4 million at December 31, 2015.