Investment Securities (Tables)

6 Months Ended

Jun. 30, 2020

Investment Securities.

Schedule of amortized cost and fair values of investment securities

	Amortized		Gross Unrealized				Estimated
(Dollars in thousands)	Cost		Gains		Losses		Fair Value
June 30, 2020:
Available-for-sale:
U.S. government-sponsored mortgage-backed securities	$	3,782	$	430	$	—	$	4,212
Total	$	3,782	$	430	$	—	$	4,212
Held-to-maturity:
U.S. government-sponsored mortgage-backed securities	$	332,533	$	19,267	$	(1)	$	351,799
Total	$	332,533	$	19,267	$	(1)	$	351,799
December 31, 2019:
Available-for-sale:
U.S. government-sponsored mortgage-backed securities	$	7,905	$	723	$	—	$	8,628
Total	$	7,905	$	723	$	—	$	8,628
Held-to-maturity:
U.S. government-sponsored mortgage-backed securities	$	363,883	$	8,436	$	(1,014)	$	371,305
Total	$	363,883	$	8,436	$	(1,014)	$	371,305

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 within 5 years	$	—	$	—
Due after 5 years through 10 years		—		—
Due after 10 years		3,782		4,212
Total	$	3,782	$	4,212
Held-to-maturity:
Due within 5 years	$	1	$	1
Due after 5 years through 10 years		66		65
Due after 10 years		332,466		351,733
Total	$	332,533	$	351,799

Schedule of realized gains and losses and proceeds from sales of securities held to maturity

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(Dollars in thousands)	2020		2019		2020		2019
Proceeds from sales	$	5,710	$	1,595	$	8,360	$	4,336
Gross gains		419		70		597		2,787
Gross losses		—		—		—		—

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)
June 30, 2020:
Held-to-maturity:
U.S. government-sponsored mortgage-backed securities	$	59	$	(1)	$	—	$	—	5	$	59	$	(1)
December 31, 2019:
Held-to-maturity:
U.S. government-sponsored mortgage-backed securities	$	55,882	$	(302)	$	34,492	$	(712)	30	$	90,374	$	(1,014)