Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Schedule of the portfolio of investment securities available-for-sale

The following table shows the portfolio of marketable securities available-for-sale at June 30, 2024 (in thousands):

	Amortized cost		Gross unrealized holding gains	Gross unrealized holding losses	Fair value
Debt issued by the U.S government and agencies:
Due after ten years	$	47,263	—	(10,292)	36,971
Debt issued by government-sponsored enterprises:
Due after one year through five years	185		—	(5)	180
Municipal securities:
Due after one year through five years	880		8	(3)	885
Due after five years through ten years	9,157		5	(1,565)	7,597
Due after ten years	58,872		13	(8,626)	50,259
Corporate debt issues:
Due after five years through ten years	14,373		20	(886)	13,507
Due after ten years	3,250		—	—	3,250
Mortgage-backed securities:
Fixed rate pass-through	228,855		83	(16,874)	212,064
Variable rate pass-through	4,093		24	(13)	4,104
Fixed rate agency CMOs	789,673		293	(135,258)	654,708
Variable rate agency CMOs	45,753		38	(125)	45,666
Total mortgage-backed securities	1,068,374		438	(152,270)	916,542
Total marketable securities available-for-sale	$	1,202,354	484	(173,647)	1,029,191

The following table shows the portfolio of marketable securities available-for-sale at December 31, 2023 (in thousands):

	Amortized cost		Gross unrealized holding gains	Gross unrealized holding losses	Fair value
Debt issued by the U.S. government and agencies:
Due after one year through five years	$	20,000	—	(1,135)	18,865
Due after ten years	49,383		—	(9,934)	39,449
Debt issued by government-sponsored enterprises:
Due after one year through five years	45,986		—	(5,763)	40,223
Due after five years through ten years	386		—	(12)	374
Municipal securities:
Due after one year through five years	4,279		22	(427)	3,874
Due after five years through ten years	20,725		—	(1,437)	19,288
Due after ten years	60,762		125	(8,580)	52,307
Corporate debt issues:
Due after five years through ten years	8,466		—	(778)	7,688
Mortgage-backed securities:
Fixed rate pass-through	209,069		27	(25,222)	183,874
Variable rate pass-through	7,140		11	(71)	7,080
Fixed rate agency CMOs	789,842		—	(143,055)	646,787
Variable rate agency CMOs	23,965		38	(453)	23,550
Total mortgage-backed securities	1,030,016		76	(168,801)	861,291
Total marketable securities available-for-sale	$	1,240,003	223	(196,867)	1,043,359

Schedule of the portfolio of investment securities held-to-maturity

The following table shows the portfolio of marketable securities held-to-maturity at June 30, 2024 (in thousands):

	Amortized cost		Gross unrealized holding gains	Gross unrealized holding losses	Fair value
Debt issued by government-sponsored enterprises:
Due after one year through five years	$	89,472	—	(10,845)	78,627
Due after five years through ten years	34,988		—	(5,645)	29,343
Mortgage-backed securities:
Fixed rate pass-through	140,245		—	(21,704)	118,541
Variable rate pass-through	414		—	(4)	410
Fixed rate agency CMOs	518,560		—	(82,714)	435,846
Variable rate agency CMOs	529		—	(4)	525
Total mortgage-backed securities	659,748		—	(104,426)	555,322
Total marketable securities held-to-maturity	$	784,208	—	(120,916)	663,292

The following table shows the portfolio of marketable securities held-to-maturity at December 31, 2023 (in thousands): 

	Amortized cost		Gross unrealized holding gains	Gross unrealized holding losses	Fair value
Debt issued by government-sponsored enterprises:
Due after one year through five years	$	69,471	—	(8,100)	61,371
Due after five years through ten years	54,987		—	(8,700)	46,287
Mortgage-backed securities:
Fixed rate pass-through	147,874		—	(20,834)	127,040
Variable rate pass-through	449		1	—	450
Fixed rate agency CMOs	541,529		—	(77,694)	463,835
Variable rate agency CMOs	529		—	(6)	523
Total mortgage-backed securities	690,381		1	(98,534)	591,848
Total marketable securities held-to-maturity	$	814,839	1	(115,334)	699,506

Schedule of contractual maturity of mortgage-backed securities

The following table shows the contractual maturity of our mortgage-backed securities available-for-sale at June 30, 2024 (in thousands):

	Amortized cost		Fair value
Mortgage-backed securities:
Due within one year	$	74	75
Due after one year through five years	11,289		11,185
Due after five years through ten years	8,021		7,022
Due after ten years	1,048,990		898,260
Total mortgage-backed securities	$	1,068,374	916,542

The following table shows the contractual maturity of our mortgage-backed securities held-to-maturity at June 30, 2024 (in thousands):

	Amortized cost		Fair value
Mortgage-backed securities:
Due within one year	$	102	100
Due after one year through five years	20,010		17,581
Due after five years through ten years	20,201		16,321
Due after ten years	619,435		521,320
Total mortgage-backed securities	$	659,748	555,322

Schedule of the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position

The following table shows the fair value of and gross unrealized losses on available-for-sale investment securities and held to maturity investment securities, for which an allowance for credit losses has not been recorded, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position at June 30, 2024 (in thousands):

	Less than 12 months			12 months or more		Total
	Fair  value		Unrealized loss	Fair  value	Unrealized loss	Fair  value	Unrealized loss
U.S. government-sponsored enterprises	$	—	—	145,120	(26,787)	145,120	(26,787)
Municipal securities	13,977		(140)	39,354	(10,054)	53,331	(10,194)
Corporate issues	2,395		(38)	7,619	(848)	10,014	(886)
Mortgage-backed securities - agency	247,747		(1,059)	1,170,983	(255,637)	1,418,730	(256,696)
Total	$	264,119	(1,237)	1,363,076	(293,326)	1,627,195	(294,563)

The following table shows the fair value of and gross unrealized losses on available-for-sale investment securities and held to maturity investment securities, for which an allowance for credit losses has not been recorded, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position at December 31, 2023 (in thousands):

	Less than 12 months			12 months or more		Total
	Fair  value		Unrealized loss	Fair  value	Unrealized loss	Fair  value	Unrealized loss
U.S. government-sponsored enterprises	$	—	—	206,569	(33,644)	206,569	(33,644)
Corporate debt issues	—		—	7,688	(778)	7,688	(778)
Municipal securities	2,753		(81)	66,046	(10,363)	68,799	(10,444)
Mortgage-backed securities - agency	17,976		(242)	1,423,707	(267,093)	1,441,683	(267,335)
Total	$	20,729	(323)	1,704,010	(311,878)	1,724,739	(312,201)

Schedule of credit quality of held-to-maturity securities

The following table presents the credit quality of our held-to-maturity securities, based on the latest information available as of June 30, 2024 (in thousands). The credit ratings are sourced from nationally recognized rating agencies, which include Moody’s and S&P, and they are presented based on asset type. All of our held-to-maturity securities were current in their payment of principal and interest as of June 30, 2024.

	AA+		Total
Held-to-maturity securities (at amortized cost):
Debt issued by the U.S. government-sponsored enterprises	$	124,460	124,460
Mortgage-backed securities	659,748		659,748
Total marketable securities held-to-maturity	$	784,208	784,208