Debt Securities Available for Sale (Tables)

9 Months Ended

Sep. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Schedule of amortized cost, gross unrealized gains, gross unrealized losses and the fair value of securities available-for-sale

Debt securities available for sale at September 30, 2022 and December 31, 2021 are summarized as follows:

	September 30, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Fair Value
	(In thousands)
U.S. government and agency obligations	$	67,491	$	—	$	(4,210)	$	63,281
Mortgage-backed securities and collateralized mortgage obligations	1,399,397		122		(175,867)		1,223,652
Municipal obligations	3,698		—		(141)		3,557
Corporate debt securities	88,565		6		(7,340)		81,231
	$	1,559,151	$	128	$	(187,558)	$	1,371,721

	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Fair Value
			(In thousands)
U.S. government and agency obligations	$	34,711	$	404	$	(236)	$	34,879
Mortgage-backed securities and collateralized mortgage obligations	1,553,491		14,141		(13,273)		1,554,359
Municipal obligations	4,159		20		—		4,179
Corporate debt securities	109,018		2,378		(966)		110,430
	$	1,701,379	$	16,943	$	(14,475)	$	1,703,847

Schedule of securities by contractual maturity

The amortized cost and fair value of debt securities available for sale at September 30, 2022, by contractual final maturity, is shown below. Expected maturities may differ from contractual maturities due to prepayment or early call options exercised by the issuer.

	September 30, 2022
	Amortized Cost		Fair Value
	(In thousands)
One year or less	$	919	$	901
More than one year to five years	68,971		65,791
More than five years to ten years	89,864		81,377
	$	159,754	$	148,069
Mortgage-backed securities and collateralized mortgage obligations	1,399,397		1,223,652
	$	1,559,151	$	1,371,721

The amortized cost and fair value of debt securities held to maturity at September 30, 2022, by contractual final maturity, is shown below. Expected maturities may differ from contractual maturities due to prepayment or early call options exercised by the issuer.

	September 30, 2022
	Amortized Cost		Fair Value
	(In thousands)
More than one year to five years	$	19,875	$	18,282
More than five years to ten years	19,996		16,479
More than ten years	10,000		7,523
	49,871		42,284
Mortgage-backed securities and collateralized mortgage obligations	375,206		331,210
	$	425,077	$	373,494

Debt securities, available-for-sale, unrealized loss position, fair value

The following tables summarize the fair value and gross unrealized losses of those securities that reported an unrealized loss at September 30, 2022 and December 31, 2021 and if the unrealized loss position was continuous for the twelve months prior to those respective dates:

	September 30, 2022
	Less Than 12 Months				12 Months or Longer				Total
	Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)
	(In thousands)
U.S. government and agency obligations	$	54,464	$	(3,104)	$	8,817	$	(1,106)	$	63,281	$	(4,210)
Mortgage-backed securities and collateralized mortgage obligations	696,364		(72,154)		504,328		(103,713)		1,200,692		(175,867)
Municipal obligations	3,557		(141)		—		—		3,557		(141)
Corporate debt securities	70,286		(6,300)		8,960		(1,040)		79,246		(7,340)
	$	824,671	$	(81,699)	$	522,105	$	(105,859)	$	1,346,776	$	(187,558)

6.    Debt Securities Available for Sale (continued)

	December 31, 2021
	Less Than 12 Months				12 Months or Longer				Total
	Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)		Fair Value		Gross Unrealized (Losses)
	(In thousands)
U.S. government and agency obligations	$	14,488	$	(236)	$	—	$	—	$	14,488	$	(236)
Mortgage-backed securities and collateralized mortgage obligations	820,746		(11,892)		62,407		(1,381)		883,153		(13,273)
Corporate debt securities	29,221		(671)		4,705		(295)		33,926		(966)
	$	864,455	$	(12,799)	$	67,112	$	(1,676)	$	931,567	$	(14,475)

Debt Securities, Available-for-sale, Allowance for Credit Loss

The following table presents the activity in the allowance for credit losses on debt securities available for sale for the three and nine months ended September 30, 2022:

	Three Months Ended September 30, 2022		Nine Months Ended September 30, 2022
	(In thousands)
Allowance for Credit Losses:
Beginning balance	$	—	$	—
Impact of adopting ASU 2016-13 (CECL) effective January 1, 2022	—		490
(Reversal of ) credit losses	—		(490)
Balance at September 30, 2022	$	—	$	—