
	September 30, 2020
(dollars in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Allowance for credit losses on investments		Fair value
Investment securities available for sale
U.S. government sponsored entities and U.S. agency securities	$	32,276	$	461	$	20	$	—	$	32,717
Mortgage-backed securities - agency	282,389		6,796		6		—		289,179
Mortgage-backed securities - non-agency	23,712		260		—		—		23,972
State and municipal securities	120,998		7,009		3		2		128,002
Corporate securities	136,652		1,375		1,760		306		135,961
Total available for sale securities	$	596,027	$	15,901	$	1,789	$	308	$	609,831


	December 31, 2019
(dollars in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Allowance for credit losses on investments	Fair value
Investment securities available for sale
U.S. government sponsored entities and U.S. agency securities	$	59,600	$	442	$	22	N/A	$	60,020
Mortgage-backed securities - agency	321,840		3,368		234		N/A	324,974
Mortgage-backed securities - non-agency	17,198		3		53		N/A	17,148
State and municipal securities	119,371		5,195		11		N/A	124,555
Corporate securities	121,159		2,131		554		N/A	122,736
Total available for sale securities	$	639,168	$	11,139	$	874	N/A	$	649,433

The following is a summary of the amortized cost and fair value of the investment securities available for sale, by maturity, at September 30, 2020. Expected maturities may differ from contractual maturities in mortgage-backed securities because the mortgages underlying the securities may be prepaid without penalties. The maturities of all other investment securities available for sale are based on final contractual maturity.


(dollars in thousands)	Amortized cost		Fair value
Investment securities available for sale
Within one year	$	28,407	$	28,730
After one year through five years	63,844		66,583
After five years through ten years	171,593		173,883
After ten years	26,082		27,484
Mortgage-backed securities	306,101		313,151
Total available for sale securities	$	596,027	$	609,831

Proceeds and gross realized gains and losses on sales on investment securities available for sale for the three and nine months ended September 30, 2020 and 2019 are summarized as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
(dollars in thousands)	2020		2019		2020		2019
Investment securities available for sale
Proceeds from sales(1)	$	28,256	$	1,025	$	28,256	$	29,490
Gross realized gains on sales	1,721		25		1,721		151
Gross realized losses on sales	—		—		—		(190)

The table below presents a rollforward by major security type for the three and nine months ended September 30, 2020 of the ACL on investment securities available for sale held at period end:


(dollars in thousands)	State and municipal securities		Corporate securities
Change in allowance for credit losses on investment securities for the three months ended September 30, 2020:
Balance, beginning of period	$	1	$	126

Additions	1		243
Reductions	—		(63)

Balance, end of period	$	2	$	306
Change in allowance for credit losses on investment securities for the nine months ended September 30, 2020:
Balance, beginning of period	$	—	$	—
Impact of adopting ASC 326	—		—
Additions	20		389
Reductions	(18)		(83)

Balance, end of period	$	2	$	306

Unrealized losses and fair values for investment securities available for sale as of September 30, 2020, for which an ACL has not been recorded, and December 31, 2019, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, are summarized as follows:


	September 30, 2020
	Less than 12 Months				12 Months or more				Total
(dollars in thousands)	Fair value		Unrealized loss		Fair value		Unrealized loss		Fair value		Unrealized loss
Investment securities available for sale
U.S. government sponsored entities and U.S. agency securities	$	9,980	$	20	$	—	$	—	$	9,980	$	20
Mortgage-backed securities - agency	2,502		6		—		—		2,502		6

Corporate securities	27,916		868		—		—		27,916		868
Total available for sale securities	$	40,398	$	894	$	—	$	—	$	40,398	$	894


	December 31, 2019
	Less than 12 Months				12 Months or more				Total
(dollars in thousands)	Fair value		Unrealized loss		Fair value		Unrealized loss		Fair value		Unrealized loss
Investment securities available for sale
U.S. government sponsored entities and U.S. agency securities	$	7,200	$	22	$	—	$	—	$	7,200	$	22
Mortgage-backed securities - agency	75,336		170		7,170		64		82,506		234
Mortgage-backed securities - non-agency	11,059		53		—		—		11,059		53
State and municipal securities	1,813		11		—		—		1,813		11
Corporate securities	20,269		481		3,915		73		24,184		554
Total available for sale securities	$	115,677	$	737	$	11,085	$	137	$	126,762	$	874

For all of the above investment securities, the unrealized losses are generally due to changes in interest rates and other market conditions, and unrealized losses are considered to be temporary as the fair value is expected to recover as the securities approach their respective maturity dates.

At September 30, 2020, 16 investment securities available for sale had unrealized losses with aggregate depreciation of 2.17% from their amortized cost basis. The unrealized losses related principally to the fluctuations in the current rate environment. In analyzing an issuer’s financial condition, we consider whether the securities are issued by the federal

government or its agencies and whether downgrades by bond rating agencies have occurred. The Company does not intend to sell and it is likely that the Company will not be required to sell the securities prior to their anticipated recovery.

Equity securities are recorded at fair value and totaled $9.1 million and $5.6 million at September 30, 2020 and December 31, 2019, respectively.

Proceeds and gross realized gains on sales of equity securities as well as net unrealized gains on equity securities for the three and nine months ended September 30, 2020 and 2019 are summarized as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
(dollars in thousands)	2020		2019		2020		2019
Equity securities
Proceeds from sales	$	—	$	—	$	—	$	105
Gross realized gains on sales	—		—		—		78

Net unrealized gains	135		54		317		92