Investment Securities (Tables)

9 Months Ended

Sep. 30, 2024

Investment Securities

Schedule of amortized cost and fair value of securities

	September 30, 2024								December 31, 2023
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
U.S. Treasury and government agency debt securities	$	13,320	$	—	$	(123)	$	13,197	$	33,169	$	—	$	(666)	$	32,503
Government-sponsored enterprises debt securities		20,000		—		(153)		19,847		20,000		—		(408)		19,592
Mortgage-backed securities:
Residential - Government agency		10,356		—		(989)		9,367		11,303		—		(1,121)		10,182
Residential - Government-sponsored enterprises		807,631		—		(84,040)		723,591		895,421		—		(112,124)		783,297
Commercial - Government agency		260,845		—		(44,835)		216,010		268,944		—		(50,270)		218,674
Commercial - Government-sponsored enterprises		73,614		—		(4,547)		69,067		93,459		—		(7,028)		86,431
Commercial - Non-agency		22,000		69		—		22,069		21,964		—		(281)		21,683
Collateralized mortgage obligations:
Government agency		487,889		—		(53,748)		434,141		538,718		—		(67,568)		471,150
Government-sponsored enterprises		386,576		—		(46,850)		339,726		425,826		—		(61,856)		363,970
Collateralized loan obligations		208,550		396		(2)		208,944		249,871		43		(2,060)		247,854
Total available-for-sale securities	$	2,290,781	$	465	$	(235,287)	$	2,055,959	$	2,558,675	$	43	$	(303,382)	$	2,255,336
Government agency debt securities	$	50,424	$	—	$	(3,421)	$	47,003	$	52,051	$	—	$	(4,497)	$	47,554
Mortgage-backed securities:
Residential - Government agency		41,584		—		(4,652)		36,932		43,885		—		(5,189)		38,696
Residential - Government-sponsored enterprises		94,039		—		(9,769)		84,270		99,379		—		(11,013)		88,366
Commercial - Government agency		30,960		—		(7,004)		23,956		30,795		—		(7,017)		23,778
Commercial - Government-sponsored enterprises		1,118,670		210		(97,680)		1,021,200		1,129,738		195		(130,757)		999,176
Collateralized mortgage obligations:
Government agency		928,546		—		(94,856)		833,690		989,130		—		(109,471)		879,659
Government-sponsored enterprises		1,534,983		—		(157,632)		1,377,351		1,642,274		—		(193,897)		1,448,377
Debt securities issued by states and political subdivisions		54,491		—		(3,750)		50,741		54,197		—		(4,947)		49,250
Total held-to-maturity securities	$	3,853,697	$	210	$	(378,764)	$	3,475,143	$	4,041,449	$	195	$	(466,788)	$	3,574,856

Schedule of amortized cost and fair value of debt securities by contractual maturity

	September 30, 2024
	Amortized		Fair
(dollars in thousands)	Cost		Value
Available-for-sale securities
Due in one year or less	$	33,320	$	33,045
Due after one year through five years		9,275		9,281
Due after five years through ten years		132,017		132,281
Due after ten years		89,258		89,450
		263,870		264,057
Mortgage-backed securities:
Residential - Government agency		10,356		9,367
Residential - Government-sponsored enterprises		807,631		723,591
Commercial - Government agency		260,845		216,010
Commercial - Government-sponsored enterprises		73,614		69,067
Total mortgage-backed securities		1,152,446		1,018,035
Collateralized mortgage obligations:
Government agency		487,889		434,141
Government-sponsored enterprises		386,576		339,726
Total collateralized mortgage obligations		874,465		773,867
Total available-for-sale securities	$	2,290,781	$	2,055,959
Held-to-maturity securities
Due in one year or less	$	—	$	—
Due after one year through five years		—		—
Due after five years through ten years		22,233		21,019
Due after ten years		82,682		76,725
		104,915		97,744
Mortgage-backed securities:
Residential - Government agency		41,584		36,932
Residential - Government-sponsored enterprises		94,039		84,270
Commercial - Government agency		30,960		23,956
Commercial - Government-sponsored enterprises		1,118,670		1,021,200
Total mortgage-backed securities		1,285,253		1,166,358
Collateralized mortgage obligations:
Government agency		928,546		833,690
Government-sponsored enterprises		1,534,983		1,377,351
Total collateralized mortgage obligations		2,463,529		2,211,041
Total held-to-maturity securities	$	3,853,697	$	3,475,143

Schedule of gross unrealized losses and fair values of securities in a continuous loss position

	Time in Continuous Loss as of September 30, 2024
	Less Than 12 Months				12 Months or More				Total
	Unrealized				Unrealized				Unrealized
(dollars in thousands)	Losses		Fair Value		Losses		Fair Value		Losses		Fair Value
U.S. Treasury and government agency debt securities	$	—	$	—	$	(123)	$	13,197	$	(123)	$	13,197
Government-sponsored enterprises debt securities		—		—		(153)		19,847		(153)		19,847
Mortgage-backed securities:
Residential - Government agency		—		—		(989)		9,367		(989)		9,367
Residential - Government-sponsored enterprises		—		—		(84,040)		723,591		(84,040)		723,591
Commercial - Government agency		—		—		(44,835)		216,010		(44,835)		216,010
Commercial - Government-sponsored enterprises		—		—		(4,547)		69,067		(4,547)		69,067
Collateralized mortgage obligations:
Government agency		—		—		(53,748)		434,141		(53,748)		434,141
Government-sponsored enterprises		—		—		(46,850)		339,726		(46,850)		339,726
Collateralized loan obligations		(2)		2,998		—		—		(2)		2,998
Total available-for-sale securities with unrealized losses	$	(2)	$	2,998	$	(235,285)	$	1,824,946	$	(235,287)	$	1,827,944

	Time in Continuous Loss as of December 31, 2023
	Less Than 12 Months				12 Months or More				Total
	Unrealized				Unrealized				Unrealized
(dollars in thousands)	Losses		Fair Value		Losses		Fair Value		Losses		Fair Value
U.S. Treasury and government agency debt securities	$	—	$	—	$	(666)	$	32,503	$	(666)	$	32,503
Government-sponsored enterprises debt securities		—		—		(408)		19,592		(408)		19,592
Mortgage-backed securities:
Residential - Government agency		—		—		(1,121)		10,182		(1,121)		10,182
Residential - Government-sponsored enterprises		—		—		(112,124)		783,297		(112,124)		783,297
Commercial - Government agency		—		—		(50,270)		218,674		(50,270)		218,674
Commercial - Government-sponsored enterprises		—		—		(7,028)		86,431		(7,028)		86,431
Commercial - Non-agency		—		—		(281)		21,683		(281)		21,683
Collateralized mortgage obligations:
Government agency		—		—		(67,568)		471,150		(67,568)		471,150
Government-sponsored enterprises		—		—		(61,856)		363,970		(61,856)		363,970
Collateralized loan obligations		(564)		63,667		(1,496)		163,126		(2,060)		226,793
Total available-for-sale securities with unrealized losses	$	(564)	$	63,667	$	(302,818)	$	2,170,608	$	(303,382)	$	2,234,275