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, 2017
(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)	$	229,367		$	1,311		$	(3,386	)	$	227,292
Non-GSE issuance REMICs and CMOs	1,141			—			(5		)	1,136
GSE pass-through certificates	8,239			339			(2		)	8,576
Total residential mortgage-backed securities	238,747			1,650			(3,393		)	237,004
Obligations of GSEs	30,000			—			(1,107		)	28,893
Fannie Mae stock	15			—			(13		)	2
Total securities available-for-sale	$	268,762		$	1,650		$	(4,513	)	$	265,899
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	1,182,307		$	4,893		$	(11,311	)	$	1,175,889
Non-GSE issuance REMICs and CMOs	191			—			(7		)	184
GSE pass-through certificates	221,058			909			(2,384		)	219,583
Total residential mortgage-backed securities	1,403,556			5,802			(13,702		)	1,395,656
Multi-family mortgage-backed securities:
GSE issuance REMICs	906,183			217			(19,581		)	886,819
Obligations of GSEs	379,316			23			(16,249		)	363,090
Corporate Debt securities	80,000			—			(4,163		)	75,837
Other	321			—			—			321
Total securities held-to-maturity	$	2,769,376		$	6,042		$	(53,695	)	$	2,721,723


(1)	Government-sponsored enterprise


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



	At December 31, 2016
(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	$	242,172		$	1,327		$	(2,706	)	$	240,793
Non-GSE issuance REMICs and CMOs	1,442			2			(1		)	1,443
GSE pass-through certificates	8,571			361			(2		)	8,930
Total residential mortgage-backed securities	252,185			1,690			(2,709		)	251,166
Obligations of GSEs	30,000			—			(1,125		)	28,875
Fannie Mae stock	15			—			(11		)	4
Total securities available-for-sale	$	282,200		$	1,690		$	(3,845	)	$	280,045
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	1,119,175		$	4,896		$	(11,957	)	$	1,112,114
Non-GSE issuance REMICs and CMOs	193			—			(7		)	186
GSE pass-through certificates	228,976			665			(3,282		)	226,359
Total residential mortgage-backed securities	1,348,344			5,561			(15,246		)	1,338,659
Multi-family mortgage-backed securities:
GSE issuance REMICs	927,119			363			(19,290		)	908,192
Obligations of GSEs	384,325			54			(16,510		)	367,869
Corporate debt securities	80,000			—			(4,518		)	75,482
Other	344			—			—			344
Total securities held-to-maturity	$	2,740,132		$	5,978		$	(55,564	)	$	2,690,546

The following contractual maturity table sets forth certain information regarding the amortized costs and estimated fair values of our securities available-for-sale and securities held-to-maturity at March 31, 2017 and does not reflect the effect of prepayments or scheduled principal amortization on our REMICs, CMOs and pass-through certificates or the effect of callable features on our obligations of GSEs (all of which are callable in 2017 and at various times thereafter).



	March 31, 2017
	Available-for-Sale						Held-to-Maturity
(Dollars in Thousands)	Amortized Cost			Estimated Fair Value			Amortized Cost		Estimated Fair Value
Securities remaining period to contractual maturity:
Within one year		$	202		$	204	$	34,977	$	34,979
Over one to five years		1,333			1,329		17,522		17,541
Over five to ten years		36,822			35,912		406,424		389,288
Over ten years		230,405			228,454		2,310,453		2,279,915
Total securities		$	268,762		$	265,899	$	2,769,376	$	2,721,723

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, 2017
	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	$	113,064		$	(2,634	)	$	19,720		$	(752	)	$	132,784		$	(3,386	)
Non-GSE issuance REMICs and CMOs	1,022			(4		)	81			(1		)	1,103			(5		)
GSE pass-through certificates	62			(1		)	59			(1		)	121			(2		)
Obligations of GSEs	28,893			(1,107		)	—			—			28,893			(1,107		)
Fannie Mae stock	—			—			2			(13		)	2			(13		)
Total temporarily impaired securities available-for-sale	$	143,041		$	(3,746	)	$	19,862		$	(767	)	$	162,903		$	(4,513	)
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	569,367		$	(7,110	)	$	125,051		$	(4,201	)	$	694,418		$	(11,311	)
Non-GSE issuance REMICs and CMOs	—			—			184			(7		)	184			(7		)
GSE pass-through certificates	81,074			(1,235		)	60,450			(1,149		)	141,524			(2,384		)
Multi-family mortgage-backed securities:
GSE issuance REMICs	834,947			(19,581		)	—			—			834,947			(19,581		)
Obligations of GSEs	311,690			(16,249		)	—			—			311,690			(16,249		)
Corporate debt securities	9,327			(673		)	66,510			(3,490		)	75,837			(4,163		)
Total temporarily impaired securities held-to-maturity	$	1,806,405		$	(44,848	)	$	252,195		$	(8,847	)	$	2,058,600		$	(53,695	)



	At December 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	$	140,638		$	(1,886	)	$	20,026		$	(820	)	$	160,664		$	(2,706	)
Non-GSE issuance REMICs and CMOs	—			—			92			(1		)	92			(1		)
GSE pass-through certificates	71			(1		)	90			(1		)	161			(2		)
Obligations of GSEs	28,875			(1,125		)	—			—			28,875			(1,125		)
Fannie Mae stock	—			—			4			(11		)	4			(11		)
Total temporarily impaired securities available-for-sale	$	169,584		$	(3,012	)	$	20,212		$	(833	)	$	189,796		$	(3,845	)
Held-to-maturity:
Residential mortgage-backed securities:
GSE issuance REMICs and CMOs	$	515,537		$	(7,457	)	$	131,629		$	(4,500	)	$	647,166		$	(11,957	)
Non-GSE issuance REMICs and CMOs	—			—			186			(7		)	186			(7		)
GSE pass-through certificates	104,538			(1,775		)	61,872			(1,507		)	166,410			(3,282		)
Multi-family mortgage-backed securities:
GSE issuance REMICs	871,436			(19,290		)	—			—			871,436			(19,290		)
Obligations of GSEs	296,427			(16,510		)	—			—			296,427			(16,510		)
Corporate debt securities	37,785			(2,216		)	37,698			(2,302		)	75,483			(4,518		)
Total temporarily impaired securities held-to-maturity	$	1,825,723		$	(47,248	)	$	231,385		$	(8,316	)	$	2,057,108		$	(55,564	)

We held 195 securities which had an unrealized loss at March 31, 2017 and 188 securities which had an unrealized loss at December 31, 2016. 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, 2017 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 were primarily due to the observed credit spread widening that occurred during the three months ended March 31, 2017, which we attribute to the contemporaneous broad-based equity market volatility. We do not consider these unrealized losses to be other than temporary impairment.

There were no sales of securities from the available-for-sale portfolio during the three months ended March 31, 2017. 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.

At March 31, 2017, available-for-sale debt securities, excluding mortgage-backed securities, had an amortized cost of $30.0 million, an estimated fair value of $28.9 million and contractual maturities in 2025 and 2026. At March 31, 2017, held-to-maturity debt securities, excluding mortgage-backed securities, had an amortized cost of $459.6 million, an estimated fair value of $439.2 million and contractual maturities primarily in 2017 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, 2017, the amortized cost of callable securities in our portfolio totaled $374.3 million, which are callable in 2017 and at various times thereafter. The balance of accrued interest receivable for securities totaled $8.3 million at March 31, 2017 and $8.1 million at December 31, 2016.