The following tables provide a summary of the amortized cost and fair values of the available-for-sale securities and held-to-maturity securities at June 30, 2020 and December 31, 2019 (in thousands):

	June 30, 2020
	Amortized Cost		Gross Unrealized Gains ⁽¹⁾		Gross Unrealized Losses ⁽¹⁾			Estimated Fair Value
Available-for-sale securities
U.S. government agency securities	$	5,037	$	109	$	—		$	5,146
State and municipal securities		2,407		54		—			2,461
Mortgage-backed securities:
Agency		750,381		20,538		(190	)		770,729
Commercial		102,341		3,106		—			105,447
Non-agency		6,921		93		(91	)		6,923
Corporate fixed income securities		536,928		21,081		(40	)		557,969
Asset-backed securities		1,758,273		3,627		(38,086	)		1,723,814
	$	3,162,288	$	48,608	$	(38,407	)	$	3,172,489
Held-to-maturity securities ⁽²⁾
Asset-backed securities	$	3,085,790	$	1,502	$	(135,550	)	$	2,951,742

	December 31, 2019
	Amortized Cost		Gross Unrealized Gains ⁽¹⁾		Gross Unrealized Losses ⁽¹⁾			Estimated Fair Value
Available-for-sale securities
U.S. government agency securities	$	5,028	$	39	$	—		$	5,067
State and municipal securities		24,198		99		—			24,297
Mortgage-backed securities:
Agency		840,659		3,070		(5,851	)		837,878
Commercial		109,982		269		(714	)		109,537
Non-agency		9,731		50		(23	)		9,758
Corporate fixed income securities		664,028		11,283		—			675,311
Asset-backed securities		1,600,415		679		(8,205	)		1,592,889
	$	3,254,041	$	15,489	$	(14,793	)	$	3,254,737
Held-to-maturity securities ⁽²⁾
Asset-backed securities	$	2,856,219	$	5,960	$	(34,296	)	$	2,827,883

Effective January 1, 2020, we adopted the new accounting standard for credit losses that requires evaluation of available-for-sale and held-to-maturity debt securities for any expected losses with recognition of an allowance for credit losses, when applicable. For more information, see Note 1 – Nature of Operations, Basis of Presentation, and Summary of Significant Accounting Policies. At June 30, 2020, we did not have an allowance for credit losses recorded on our investment portfolio.

Accrued interest receivable for our investment portfolio at June 30, 2020 was $32.9 million and is reported in other assets in the consolidated statements of financial condition. We do not include reserves for interest receivable in the measurement of the allowance for credit losses.

For the three and six months ended June 30, 2020, we received proceeds of $203.6 million and $491.9 million, respectively, from the sale of available-for-sale securities, which resulted in a realized gain of $0.2 million and a realized loss of $0.5 million for the three and six months ended June 30, 2020, respectively. For the three and six months ended June 30, 2019, we received proceeds of $155.3 million from the sale of available-for-sale securities, which resulted in a realized loss of $0.3 million.

During the three months ended June 30, 2020 and June 30, 2019, unrealized gains, net of deferred taxes, of $76.6 million and unrealized gains, net of deferred taxes, of $16.3 million were recorded in accumulated other comprehensive loss in the consolidated statements of financial condition. During the six months ended June 30, 2020 and June 30, 2019, unrealized gains, net of deferred taxes, of $3.3 million and unrealized gains, net of deferred taxes, of $42.1 million were recorded in accumulated other comprehensive loss in the consolidated statements of financial condition.

The table below summarizes the amortized cost and fair values of our securities by contractual maturity at June 30, 2020 and December 31, 2019 (in thousands). Expected maturities may differ significantly from contractual maturities, as issuers may have the right to call or prepay obligations with or without call or prepayment penalties.

	June 30, 2020				December 31, 2019
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Available-for-sale securities
Within one year	$	46,942	$	47,352	$	6,861	$	6,871
After one year through three years		174,027		176,920		229,184		229,760
After three years through five years		288,460		302,659		422,236		429,909
After five years through ten years		488,368		484,418		409,664		411,680
After ten years		2,164,491		2,161,140		2,186,096		2,176,517
	$	3,162,288	$	3,172,489	$	3,254,041	$	3,254,737
Held-to-maturity securities
After five years through ten years	$	853,300	$	822,035	$	598,250	$	597,166
After ten years		2,232,490		2,129,707		2,257,969		2,230,717
	$	3,085,790	$	2,951,742	$	2,856,219	$	2,827,883

The maturities of our available-for-sale (fair value) and held-to-maturity (amortized cost) securities at June 30, 2020, are as follows (in thousands):

	Within 1 Year		1-5 Years		5-10 Years		After 10 Years		Total
Available-for-sale securities ⁽¹⁾
U.S. government agency securities	$	1,915	$	3,231	$	—	$	—	$	5,146
State and municipal securities		—		—		2,461		—		2,461
Mortgage-backed securities:
Agency		23		561		753		769,392		770,729
Commercial		—		26,517		—		78,930		105,447
Non-agency		—		6,135		—		788		6,923
Corporate fixed income securities		45,414		443,135		69,420		—		557,969
Asset-backed securities		—		—		411,784		1,312,030		1,723,814
	$	47,352	$	479,579	$	484,418	$	2,161,140	$	3,172,489
Held-to-maturity securities
Asset-backed securities	$	—	$	—	$	853,300	$	2,232,490	$	3,085,790

At June 30, 2020 and December 31, 2019, securities of $249.5 million and $801.5 million, respectively, were pledged at the Federal Home Loan Bank as collateral for borrowings and letters of credit obtained to secure public deposits. At June 30, 2020 and December 31, 2019, securities of $1.1 billion and $816.1 million, respectively, were pledged with the Federal Reserve discount window.

The following table shows the gross unrealized losses and fair value of the Company’s investment securities with unrealized losses, aggregated by investment category and length of time the individual investment securities have been in continuous unrealized loss positions, at June 30, 2020 (in thousands):

	Less than 12 months					12 months or more					Total
	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
Available-for-sale securities
Mortgage-backed securities:
Agency	$	(101	)	$	5,933	$	(89	)	$	12,619	$	(190	)	$	18,552
Non-agency		—			—		(91	)		788		(91	)		788
Corporate fixed income securities		(40	)		27,658		—			—		(40	)		27,658
Asset-backed securities		(22,110	)		1,076,645		(15,976	)		493,279		(38,086	)		1,569,924
	$	(22,251	)	$	1,110,236	$	(16,156	)	$	506,686	$	(38,407	)	$	1,616,922

At June 30, 2020, the amortized cost of 110 securities classified as available for sale exceeded their fair value by $38.4 million, of which $16.2 million related to investment securities that had been in a loss position for 12 months or longer. The total fair value of these investments at June 30, 2020, was $1.6 billion, which was 51.0% of our available-for-sale portfolio.

The Company uses Moody credit ratings as the credit quality indicator for its held-to-maturity debt securities. Each security is evaluated at least quarterly. The indicators represent the rating for debt securities, as of the date presented, based on the most recent assessment performed. The following table shows the amortized cost of our held-to-maturity securities by credit quality indicator at June 30, 2020 (in thousands):

	AAA		AA		A		C		Total
Held-to-maturity securities
Asset-backed securities	$	109,469	$	2,958,157	$	15,500	$	2,664	$	3,085,790