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, 2019 and December 31, 2018 (in thousands):

	June 30, 2019
	Amortized Cost		Gross Unrealized Gains ⁽¹⁾		Gross Unrealized Losses ⁽¹⁾			Estimated Fair Value
Available-for-sale securities
U.S. government agency securities	$	299	$	1	$	—		$	300
State and municipal securities		43,073		228		—			43,301
Mortgage-backed securities:
Agency		201,205		724		(1,434	)		200,495
Commercial		78,399		266		(700	)		77,965
Non-agency		1,110		—		(20	)		1,090
Corporate fixed income securities		788,255		9,982		(716	)		797,521
Asset-backed securities		1,590,075		520		(8,207	)		1,582,388
	$	2,702,416	$	11,721	$	(11,077	)	$	2,703,060
Held-to-maturity securities ⁽²⁾
Mortgage-backed securities:
Agency	$	1,105,865	$	13,023	$	(7,863	)	$	1,111,025
Commercial		37,262		732		—			37,994
Non-agency		10,377		161		—			10,538
Asset-backed securities		2,807,210		7,778		(27,763	)		2,787,225
	$	3,960,714	$	21,694	$	(35,626	)	$	3,946,782

	December 31, 2018
	Amortized Cost		Gross Unrealized Gains ⁽¹⁾		Gross Unrealized Losses ⁽¹⁾			Estimated Fair Value
Available-for-sale securities
U.S. government agency securities	$	5,237	$	13	$	(35	)	$	5,215
State and municipal securities		72,487		—		(4,261	)		68,226
Mortgage-backed securities:
Agency		234,292		88		(3,972	)		230,408
Commercial		74,411		4		(4,700	)		69,715
Non-agency		1,245		—		(26	)		1,219
Corporate fixed income securities		958,406		—		(26,802	)		931,604
Asset-backed securities		1,779,496		672		(16,108	)		1,764,060
	$	3,125,574	$	777	$	(55,904	)	$	3,070,447
Held-to-maturity securities ⁽²⁾
Mortgage-backed securities:
Agency	$	1,198,442	$	1,307	$	(31,689	)	$	1,168,060
Commercial		51,524		185		—			51,709
Asset-backed securities		2,968,888		4,585		(70,335	)		2,903,138
	$	4,218,854	$	6,077	$	(102,024	)	$	4,122,907

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. There were no sales of available-for-sale securities during the six months ended June 30, 2018.

During the three months ended June 30, 2019 and June 30, 2018, unrealized gains, net of deferred taxes, of $16.3 million and unrealized losses, net of deferred taxes of $11.9 million were recorded in accumulated other comprehensive loss in the consolidated statements of financial condition. During the six months ended June 30, 2019 and June 30, 2018, unrealized gains, net of deferred taxes, of $42.1 million and unrealized losses, net of deferred taxes, of $24.9 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 available-for-sale and held-to-maturity securities by contractual maturity. 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, 2019
	Available-for-sale securities				Held-to-maturity securities
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Debt securities
Within one year	$	699	$	699	$	—	$	—
After one year through three years		177,610		177,324		—		—
After three years through five years		392,026		394,578		—		—
After five years through ten years		511,594		518,641		564,030		562,785
After ten years		1,339,773		1,332,268		2,243,180		2,224,440
Mortgage-backed securities
Within one year		1,318		1,894		—		—
After one year through three years		3,371		3,411		47,639		48,531
After three years through five years		987		996		—		—
After five years through ten years		5,339		5,281		149,756		150,460
After ten years		269,699		267,968		956,109		960,566
	$	2,702,416	$	2,703,060	$	3,960,714	$	3,946,782

The maturities of our available-for-sale (fair value) and held-to-maturity (amortized cost) securities at June 30, 2019, are as follows (in thousands):

	Within 1 Year		1-5 Years		5-10 Years		After 10 Years		Total
Available-for-sale: ⁽¹⁾
U.S. government agency securities	$	300	$	—	$	—	$	—	$	300
State and municipal securities		—		—		12,424		30,877		43,301
Mortgage-backed securities:
Agency		1,842		4,347		5,281		189,025		200,495
Commercial		52		60		—		77,853		77,965
Non-agency		—		—		—		1,090		1,090
Corporate fixed income securities		399		571,902		225,220		—		797,521
Asset-backed securities		—		—		280,997		1,301,391		1,582,388
	$	2,593	$	576,309	$	523,922	$	1,600,236	$	2,703,060
Held-to-maturity:
Mortgage-backed securities:
Agency	$	—	$	—	$	149,756	$	956,109	$	1,105,865
Commercial		—		37,262		—		—		37,262
Non-agency		—		10,377		—		—		10,377
Asset-backed securities		—		—		564,030		2,243,180		2,807,210
	$	—	$	47,639	$	713,786	$	3,199,289	$	3,960,714

At June 30, 2019 and December 31, 2018, securities of $1.3 billion and $1.9 billion, 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, 2019 and December 31, 2018, securities of $1.3 billion and $1.6 billion, 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, 2019 (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
Agency	$	(440	)	$	44,877	$	(994	)	$	73,702	$	(1,434	)	$	118,579
Commercial		(39	)		4,023		(661	)		72,534		(700	)		76,557
Non-agency		(20	)		1,090		—			—		(20	)		1,090
Corporate fixed income securities		(18	)		27,687		(698	)		134,002		(716	)		161,689
Asset-backed securities		(4,320	)		776,404		(3,887	)		217,160		(8,207	)		993,564
	$	(4,837	)	$	854,081	$	(6,240	)	$	497,398	$	(11,077	)	$	1,351,479
Held-to-maturity securities
Mortgage-backed securities:
Agency	$	—		$	—	$	(7,863	)	$	530,832	$	(7,863	)	$	530,832
Asset-backed securities		(9,079	)		1,164,381		(18,684	)		1,027,748		(27,763	)		2,192,129
	$	(9,079	)	$	1,164,381	$	(26,547	)	$	1,558,580	$	(35,626	)	$	2,722,961

At June 30, 2019, the amortized cost of 143 securities classified as available for sale exceeded their fair value by $11.1 million, of which $6.2 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, 2019, was $1.4 billion, which was 50.0% of our available-for-sale portfolio.

At June 30, 2019, the carrying value of 136 securities held to maturity exceeded their fair value by $35.6 million, of which $26.5 million related to securities held to maturity that have been in a loss position for 12 months or longer. As discussed in more detail below, we conduct periodic reviews of all securities with unrealized losses to assess whether the impairment is other-than-temporary.

We evaluate all securities in an unrealized loss position quarterly to assess whether the impairment is other-than-temporary. Our other-than-temporary impairment (“OTTI”) assessment is a subjective process requiring the use of judgments and assumptions. There was no credit-related OTTI recognized during the three and six months ended June 30, 2019 and 2018.

We believe the gross unrealized losses of $46.7 million related to our investment portfolio, as of June 30, 2019, are attributable to issuer-specific credit spreads and changes in market interest rates and asset spreads. We, therefore, do not expect to incur any credit losses related to these securities. In addition, we have no intent to sell these securities with unrealized losses, and it is not more likely than not that we will be required to sell these securities prior to recovery of the amortized cost. Accordingly, we have concluded that the impairment on these securities is not other-than-temporary.