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 September 30, 2019 and December 31, 2018 (in thousands):

	September 30, 2019
	Amortized Cost		Gross Unrealized Gains ⁽¹⁾		Gross Unrealized Losses ⁽¹⁾			Estimated Fair Value
Available-for-sale securities
U.S. government agency securities	$	4,565	$	48	$	(3	)	$	4,610
State and municipal securities		31,366		144		—			31,510
Mortgage-backed securities:
Agency		892,207		2,604		(7,051	)		887,760
Commercial		114,052		627		(181	)		114,498
Non-agency		10,468		70		(27	)		10,511
Corporate fixed income securities		664,800		10,183		(105	)		674,878
Asset-backed securities		1,733,203		601		(8,770	)		1,725,034
	$	3,450,661	$	14,277	$	(16,137	)	$	3,448,801
Held-to-maturity securities ⁽²⁾
Asset-backed securities	$	2,881,484	$	7,385	$	(33,078	)	$	2,855,791

	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 nine months ended September 30, 2019, we received proceeds of $486.5 million and $641.8 million, respectively, from the sale of available-for-sale securities, which resulted in an immaterial realized gain for the third quarter of 2019 and a realized loss of $0.3 million for the nine months ended September 30, 2019. For the three and nine months ended September 30, 2018, we received proceeds of $55.4 million from the sale of available-for-sale securities, which resulted in a realized loss of $0.4 million.

During the third quarter of 2019, the Company transferred certain mortgage-backed securities from the held-to-maturity category to available-for sale. As of August 1, 2019, the securities reclassified had a fair value of $1.1 billion and resulted in a net of tax increase to other comprehensive income of $17.9 million for the three and nine months ended September 30, 2019.

During the three months ended September 30, 2019 and September 30, 2018, unrealized losses, net of deferred taxes, of $1.6 million and $3.1 million were recorded in accumulated other comprehensive loss in the consolidated statements of financial condition. During the nine months ended September 30, 2019 and September 30, 2018, unrealized gains, net of deferred taxes, of $40.5 million and unrealized losses, net of deferred taxes, of $28.1 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 September 30, 2019 and December 31, 2018. 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.

	September 30, 2019				December 31, 2018
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Available-for-sale securities
Within one year	$	1,899	$	1,897	$	5,872	$	5,855
After one year through three years		226,534		226,822		234,101		227,951
After three years through five years		413,589		419,809		407,507		397,372
After five years through ten years		412,619		415,878		469,566		458,442
After ten years		2,396,020		2,384,395		2,008,528		1,980,827
	$	3,450,661	$	3,448,801	$	3,125,574	$	3,070,447
Held-to-maturity securities
Within one year	$	—	$	—	$	—	$	—
After one year through three years		—		—		51,524		51,709
After three years through five years		—		—		—		—
After five years through ten years		495,850		494,530		536,717		530,616
After ten years		2,385,634		2,361,261		3,630,613		3,540,582
	$	2,881,484	$	2,855,791	$	4,218,854	$	4,122,907

The maturities of our available-for-sale (fair value) and held-to-maturity (amortized cost) securities at September 30, 2019, 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	$	1,597	$	3,013	$	—	$	—	$	4,610
State and municipal securities		—		—		5,854		25,656		31,510
Mortgage-backed securities:
Agency		—		950		26,463		860,347		887,760
Commercial		—		36,091		—		78,407		114,498
Non-agency		—		9,483		—		1,028		10,511
Corporate fixed income securities		300		597,094		77,484		—		674,878
Asset-backed securities		—		—		306,077		1,418,957		1,725,034
	$	1,897	$	646,631	$	415,878	$	2,384,395	$	3,448,801
Held-to-maturity securities
Asset-backed securities	$	—	$	—	$	495,850	$	2,385,634	$	2,881,484

At September 30, 2019 and December 31, 2018, securities of $675.5 million 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 September 30, 2019 and December 31, 2018, securities of $946.4 million 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 September 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
U.S. government securities	$	—		$	—	$	(3	)	$	1,746	$	(3	)	$	1,746
Mortgage-backed securities:
Agency		(4,945	)		485,290	$	(2,106	)	$	182,398		(7,051	)		667,688
Commercial		(162	)		36,263		(19	)		2,216		(181	)		38,479
Non-agency		—			—		(27	)		1,027		(27	)		1,027
Corporate fixed income securities		(19	)		44,242		(86	)		57,443		(105	)		101,685
Asset-backed securities		(5,241	)		702,155		(3,529	)		239,386		(8,770	)		941,541
	$	(10,367	)	$	1,267,950	$	(5,770	)	$	484,216	$	(16,137	)	$	1,752,166
Held-to-maturity securities
Asset-backed securities	$	(3,899	)	$	572,590	$	(29,179	)	$	1,515,354	$	(33,078	)	$	2,087,944

At September 30, 2019, the amortized cost of 137 securities classified as available for sale exceeded their fair value by $16.1 million, of which $5.8 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 September 30, 2019, was $1.8 billion, which was 50.8% of our available-for-sale portfolio.

At September 30, 2019, the carrying value of 108 securities held to maturity exceeded their fair value by $33.1 million, of which $29.2 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 nine months ended September 30, 2019 and 2018.

We believe the gross unrealized losses of $49.2 million related to our investment portfolio, as of September 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.