Investment Securities (Tables)

9 Months Ended

Sep. 30, 2022

Investment Securities

Schedule of amortized cost and fair value of securities

	September 30, 2022								December 31, 2021
	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	$	165,713	$	—	$	(13,191)	$	152,522	$	196,662	$	125	$	(4,224)	$	192,563
Government-sponsored enterprises debt securities		45,000		—		(674)		44,326		—		—		—		—
Mortgage-backed securities:
Residential - Government agency		68,969		—		(7,335)		61,634		135,764		1,791		(291)		137,264
Residential - Government-sponsored enterprises		1,366,912		—		(169,071)		1,197,841		1,496,605		6,914		(12,419)		1,491,100
Commercial - Government agency		290,614		—		(39,949)		250,665		392,443		1,741		(6,521)		387,663
Commercial - Government-sponsored enterprises		142,053		—		(10,732)		131,321		1,415,511		2,646		(48,714)		1,369,443
Commercial - Non-agency		21,960		—		(290)		21,670		—		—		—		—
Collateralized mortgage obligations:
Government agency		769,161		—		(74,948)		694,213		2,103,187		7,768		(31,432)		2,079,523
Government-sponsored enterprises		553,090		—		(63,642)		489,448		2,671,131		3,608		(53,695)		2,621,044
Collateralized loan obligations		249,924		51		(4,455)		245,520		105,245		2		—		105,247
Debt securities issued by states and political subdivisions		—		—		—		—		44,185		—		—		44,185
Total available-for-sale securities	$	3,673,396	$	51	$	(384,287)	$	3,289,160	$	8,560,733	$	24,595	$	(157,296)	$	8,428,032
Government agency debt securities	$	55,069	$	—	$	(5,579)	$	49,490	$	—	$	—	$	—	$	—
Mortgage-backed securities:
Residential - Government agency		46,695		—		(5,228)		41,467		—		—		—		—
Residential - Government-sponsored enterprises		108,145		—		(11,927)		96,218		—		—		—		—
Commercial - Government agency		30,500		—		(4,784)		25,716		—		—		—		—
Commercial - Government-sponsored enterprises		1,159,512		—		(135,284)		1,024,228		—		—		—		—
Collateralized mortgage obligations:
Government agency		1,106,231		—		(97,089)		1,009,142		—		—		—		—
Government-sponsored enterprises		1,846,258		—		(178,011)		1,668,247		—		—		—		—
Debt securities issued by states and political subdivisions		53,733		—		(7,528)		46,205		—		—		—		—
Total held-to-maturity securities	$	4,406,143	$	—	$	(445,430)	$	3,960,713	$	—	$	—	$	—	$	—

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

	September 30, 2022
	Amortized		Fair
(dollars in thousands)	Cost		Value
Available-for-sale securities
Due in one year or less	$	55,063	$	54,493
Due after one year through five years		80,038		76,346
Due after five years through ten years		182,578		172,565
Due after ten years		164,918		160,634
		482,597		464,038
Mortgage-backed securities:
Residential - Government agency		68,969		61,634
Residential - Government-sponsored enterprises		1,366,912		1,197,841
Commercial - Government agency		290,614		250,665
Commercial - Government-sponsored enterprises		142,053		131,321
Total mortgage-backed securities		1,868,548		1,641,461
Collateralized mortgage obligations:
Government agency		769,161		694,213
Government-sponsored enterprises		553,090		489,448
Total collateralized mortgage obligations		1,322,251		1,183,661
Total available-for-sale securities	$	3,673,396	$	3,289,160
Held-to-maturity securities
Due in one year or less	$	—	$	—
Due after one year through five years		—		—
Due after five years through ten years		—		—
Due after ten years		108,802		95,695
		108,802		95,695
Mortgage-backed securities:
Residential - Government agency		46,695		41,467
Residential - Government-sponsored enterprises		108,145		96,218
Commercial - Government agency		30,500		25,716
Commercial - Government-sponsored enterprises		1,159,512		1,024,228
Total mortgage-backed securities		1,344,852		1,187,629
Collateralized mortgage obligations:
Government agency		1,106,231		1,009,142
Government-sponsored enterprises		1,846,258		1,668,247
Total collateralized mortgage obligations		2,952,489		2,677,389
Total held-to-maturity securities	$	4,406,143	$	3,960,713

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

	Time in Continuous Loss as of September 30, 2022
	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	$	(3,200)	$	83,558	$	(9,991)	$	68,964	$	(13,191)	$	152,522
Government-sponsored enterprises debt securities		(674)		44,326		—		—		(674)		44,326
Mortgage-backed securities:
Residential - Government agency		(7,335)		61,634		—		—		(7,335)		61,634
Residential - Government-sponsored enterprises		(134,845)		994,823		(34,226)		203,018		(169,071)		1,197,841
Commercial - Government agency		(13,928)		117,444		(26,021)		133,221		(39,949)		250,665
Commercial - Government-sponsored enterprises		(7,080)		106,268		(3,652)		25,053		(10,732)		131,321
Commercial - Non-agency		(290)		21,670		—		—		(290)		21,670
Collateralized mortgage obligations:
Government agency		(74,722)		691,942		(226)		2,271		(74,948)		694,213
Government-sponsored enterprises		(25,190)		258,825		(38,452)		230,623		(63,642)		489,448
Collateralized loan obligations:		(4,455)		169,242		—		—		(4,455)		169,242
Total available-for-sale securities with unrealized losses	$	(271,719)	$	2,549,732	$	(112,568)	$	663,150	$	(384,287)	$	3,212,882

	Time in Continuous Loss as of December 31, 2021
	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	$	(3,355)	$	134,468	$	(869)	$	16,642	$	(4,224)	$	151,110
Mortgage-backed securities:
Residential - Government agency		(291)		51,231		—		—		(291)		51,231
Residential - Government-sponsored enterprises		(10,876)		1,230,104		(1,543)		32,415		(12,419)		1,262,519
Commercial - Government agency		(5,239)		186,024		(1,282)		26,063		(6,521)		212,087
Commercial - Government-sponsored enterprises		(22,179)		744,819		(26,535)		397,123		(48,714)		1,141,942
Collateralized mortgage obligations:
Government agency		(31,432)		1,441,848		—		—		(31,432)		1,441,848
Government-sponsored enterprises		(52,551)		2,255,535		(1,144)		24,959		(53,695)		2,280,494
Total available-for-sale securities with unrealized losses	$	(125,923)	$	6,044,029	$	(31,373)	$	497,202	$	(157,296)	$	6,541,231