The following tables summarize the Company’s portfolio of debt securities available for sale and equity investments with readily determinable fair values at December 31, 2020 and 2019:

		December 31, 2020
(in thousands)		Amortized Cost			Gross Unrealized Gain			Gross Unrealized Loss			Fair Value
Debt securities available-for-sale
Mortgage-Related Debt Securities:
GSE certificates	$		1,155,436	$		54,310	$		136	$		1,209,610
GSE CMOs			1,786,896			44,691			2,872			1,828,715
Total mortgage-related debt securities	$		2,942,332	$		99,001	$		3,008	$		3,038,325
Other Debt Securities:
U. S. Treasury obligations	$		64,984	$		1	$		—	$		64,985
GSE debentures			1,158,253			3,998			3,949			1,158,302
Asset-backed securities ⁽¹⁾			530,226			2,576			5,703			527,099
Municipal bonds			25,776			625			90			26,311
Corporate bonds			870,745			17,928			6,447			882,226
Foreign notes			25,000			538			—			25,538
Capital trust notes			95,507			5,540			10,500			90,547
Total other debt securities	$		2,770,491	$		31,206	$		26,689	$		2,775,008
Total debt securities available for sale	$		5,712,823	$		130,207	$		29,697	$		5,813,333
Equity securities:
Preferred stock			15,292			201			—			15,493
Mutual funds			15,814			269			—			16,083
Total equity securities	$		31,106	$		470	$		—	$		31,576
Total securities ⁽²⁾	$		5,743,929	$		130,677	$		29,697	$		5,844,909

	December 31, 2019
(in thousands)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
Debt securities available-for-sale
Mortgage-Related Debt Securities:
GSE certificates	$	1,530,317	$	26,069	$	3,763	$	1,552,623
GSE CMOs		1,783,440		21,213		3,541		1,801,112
Total mortgage-related debt securities	$	3,313,757	$	47,282	$	7,304	$	3,353,735
Other Debt Securities:
U. S. Treasury obligations	$	41,820	$	19	$	—	$	41,839
GSE debentures		1,093,845		5,707		5,312		1,094,240
Asset-backed securities ⁽¹⁾		384,108		—		10,854		373,254
Municipal bonds		26,808		559		475		26,892
Corporate bonds		854,195		15,970		2,983		867,182
Capital trust notes		95,100		7,121		6,306		95,915
Total other debt securities	$	2,495,876	$	29,376	$	25,930	$	2,499,322
Total other securities available for sale	$	5,809,633	$	76,658	$	33,234	$	5,853,057
Equity securities:
Preferred stock		15,292		122		—		15,414
Mutual funds and common stock ⁽²⁾		16,871		718		173		17,416
Total equity securities	$	32,163	$	840	$	173	$	32,830
Total securities ⁽³⁾	$	5,841,796	$	77,498	$	33,407	$	5,885,887

At December 31, 2020 and 2019, respectively, the Company had $714.0 million and $647.6 million of FHLB-NY stock, at cost. The Company maintains an investment in FHLB-NY stock partly in conjunction with its membership in the FHLB and partly related to its access to the FHLB funding it utilizes.

The following table summarizes the gross proceeds, gross realized gains, and gross realized losses from the sale of available-for-sale securities during the years ended December 31, 2020, 2019, and 2018:

Net unrealized gains on equity securities recognized in earnings for the years ended December 31, 2020 and 2019, were $582,000 and $2.3 million, respectively. Net unrealized losses on equity securities recognized in earnings for the year ended December 31, 2018 were $2.0 million.

The following table summarizes, by contractual maturity, the amortized cost of securities at December 31, 2020:

		Mortgage- Related Securities		Average Yield				U.S. Government and GSE Obligations		Average Yield				State, County, and Municipal		Average Yield ⁽¹⁾				Other Debt Securities ⁽²⁾		Average Yield			Fair Value
(dollars in thousands)
Available-for-Sale Debt Securities:
Due within one year	$		49,797		3.03	%	$		75,934		0.56	%	$		—		—	%	$		49,704		3.02	$		176,720
Due from one to five years			405,157		3.16				21,924		3.52				—		—				151,873		2.22			615,048
Due from five to ten years			175,689		2.48				138,053		2.37				19,898		3.51				779,401		1.88			1,130,037
Due after ten years			2,311,689		2.15				987,326		1.60				5,878		3.33				540,500		1.29			3,891,528
Total debt securities available for sale	$		2,942,332		2.32		$		1,223,237		1.66		$		25,776		3.47		$		1,521,478		1.74	$		5,813,333

The following table presents securities having a continuous unrealized loss position for less than twelve months and for twelve months or longer as of December 31, 2020:

		Less than Twelve Months						Twelve Months or Longer						Total
(in thousands)		Fair Value			Unrealized Loss			Fair Value			Unrealized Loss			Fair Value			Unrealized Loss
Temporarily Impaired Securities:
U. S. Treasury obligations	$		—	$		—	$		—	$		—	$		—	$		—
GSE certificates			58,876			136			—			—			58,876			136
GSE CMOs			442,207			2,807			73,568			65			515,775			2,872
GSE debenture			522,441			3,949			—			—			522,441			3,949
Asset-backed securities			—			—			363,618			5,703			363,618			5,703
Municipal bonds			—			—			8,891			90			8,891			90
Corporate bonds			72,024			2,976			246,528			3,471			318,552			6,447
Foreign notes			—			—			—			—			—			—
Capital trust notes			—			—			33,393			10,500			33,393			10,500
Equity securities			—			—			—			—			—			—
Total temporarily impaired securities	$		1,095,548	$		9,868	$		725,998	$		19,829	$		1,821,546	$		29,697

The following table presents securities having a continuous unrealized loss position for less than twelve months and for twelve months or longer as of December 31, 2019:

	Less than Twelve Months				Twelve Months or Longer				Total
(in thousands)	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Temporarily Impaired Securities:
U. S. Treasury Obligations	$	11,917	$	-	$	-	$	-	$	11,917	$	-
GSE debentures		297,179		3,916		138,189		1,396		435,368		5,312
GSE certificates		396,930		3,718		7,542		45		404,472		3,763
GSE CMOs		609,502		2,582		133,955		959		743,457		3,541
Asset-backed securities		256,619		7,701		116,635		3,154		373,254		10,855
Municipal bonds		—		—		9,349		475		9,349		475
Corporate bonds		99,300		700		172,717		2,282		272,017		2,982
Capital trust notes		—		—		37,525		6,306		37,525		6,306
Equity securities		—		—		11,633		173		11,633		173
Total temporarily impaired securities	$	1,671,447	$	18,617	$	627,545	$	14,790	$	2,298,992	$	33,407

The investment securities designated as having a continuous loss position for twelve months or more at December 31, 2020 consisted of four agency collateralized mortgage obligations, five capital trusts notes, seven asset-backed securities, three corporate bonds, and one municipal bond. The investment securities designated as having a continuous loss position for twelve months or more at December 31, 2019 consisted of seven US Government agency securities, five capital trusts notes, three agency mortgage-related securities, three agency CMOs, three asset-backed securities, two corporate bonds, one municipal bond, and one mutual fund.

The Company evaluates available-for-sale debt securities in unrealized loss positions at least quarterly to determine if an allowance for credit losses is required. Based on an evaluation of available information about past events, current conditions, and reasonable and supportable forecasts that are relevant to collectability, the Company has concluded that it expects to receive all contractual cash flows from each security held in its available-for-sale securities portfolio.

We first assess whether (i) we intend to sell, or (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. If either of these criteria is met, any previously recognized allowances are charged off and the security’s amortized cost basis is written down to fair value through income. If neither of the aforementioned criteria are met, we evaluate whether the decline in fair value has resulted from credit losses or other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income.

None of the unrealized losses identified as of December 31, 2020 or December 31, 2019 relates to the marketability of the securities or the issuers’ ability to honor redemption obligations. Rather, the unrealized losses relate to changes in interest rates relative to when the investment securities were purchased, and do not indicate credit-related impairment. Management based this conclusion on an analysis of each issuer including a detailed credit assessment of each issuer. The Company does not intend to sell, and it is not more likely than not that the Company will be required to sell the positions before the recovery of their amortized cost basis, which may be at maturity. As such, no allowance for credit losses was recorded with respect to debt securities as of or during the nine months ended December 31, 2020.

Management has made the accounting policy election to exclude accrued interest receivable on available-for-sale securities from the estimate of credit losses. Available-for-sale debt securities are placed on non-accrual status when we no longer expect to receive all contractual amounts due, which is generally at 90 days past due. Accrued interest receivable is reversed against interest income when a security is placed on non-accrual status.