Investment Securities (Tables)

12 Months Ended

Dec. 31, 2023

Investment Securities

Schedule of amortized cost and fair values of investment securities

The amortized cost and fair values of investment securities are as follows:

	Amortized		Gross Unrealized				Estimated
(Dollars in thousands)	Cost		Gains		Losses		Fair Value			ACL
December 31, 2023:
Available-for-sale:
Mortgage-backed securities issued by U.S. government-sponsored enterprises	$	22,563	$	—	$	(2,392)	$	20,171	$	—
Held-to-maturity:
Mortgage-backed securities issued by U.S. government agencies or U.S. government-sponsored enterprises		685,728		68		(117,668)		568,128		—
Total	$	708,291	$	68	$	(120,060)	$	588,299	$	—
December 31, 2022:
Available-for-sale:
Mortgage-backed securities issued by U.S. government-sponsored enterprises	$	23,544	$	—	$	(2,723)	$	20,821
Held-to-maturity:
Mortgage-backed securities issued by U.S. government agencies or U.S. government-sponsored enterprises		717,773		62		(126,751)		591,084
Total	$	741,317	$	62	$	(129,474)	$	611,905

Schedule of amortized cost and estimated fair value of investment securities by maturity

	Amortized		Estimated
(Dollars in thousands)	Cost		Fair Value
Available-for-sale:
Due after 10 years	$	22,563	$	20,171
Total	$	22,563	$	20,171
Held-to-maturity:
Due within 5 years	$	14	$	14
Due after 5 years through 10 years		7		6
Due after 10 years		685,707		568,108
Total	$	685,728	$	568,128

Summary of investment securities in an unrealized loss position

	Less Than 12 Months				12 Months or Longer				Total
			Unrealized				Unrealized		Number of			Unrealized
Description of securities	Fair Value		Losses		Fair Value		Losses		Securities	Fair Value		Losses
(Dollars in thousands)
December 31, 2023:
Available-for-sale:
Mortgage-backed securities issued by U.S. government-sponsored enterprises	$	—	$	—	$	20,171	$	(2,392)	4	$	20,171	$	(2,392)
Held-to-maturity:
Mortgage-backed securities issued by U.S. government agencies or U.S. government-sponsored enterprises		10,326		(107)		554,514		(117,561)	152		564,840		(117,668)
Total	$	10,326	$	(107)	$	574,685	$	(119,953)	156	$	585,011	$	(120,060)
December 31, 2022:
Available-for-sale:		—		—		—		—	—		—		—
Mortgage-backed securities issued by U.S. government sponsored enterprises	$	20,821	$	(2,723)	$	—	$	—	4	$	20,821	$	(2,723)
Held-to-maturity:
Mortgage-backed securities issued by U.S. government agencies or U.S. government-sponsored enterprises		210,128		(22,209)		377,418		(104,542)	148		587,546		(126,751)
Total	$	230,949	$	(24,932)	$	377,418	$	(104,542)	152	$	608,367	$	(129,474)