The amortized cost and estimated fair value of investment securities are summarized below. The majority of securities held are

available-for-sale

securities with fair value based on quoted prices for similar assets in active markets or quoted prices for identical assets in markets that are not active. Estimated fair values were obtained from an independent pricing service based upon market quotes.

	March 31, 2020
	Amortized Cost		Gross Unrealized Holding Gain		Gross Unrealized Holding Loss		Fair Value		Total Percent
	(Dollars in thousands)
Investment securities available-for-sale:
Mortgage-backed securities	$	1,118,385	$	43,546	$	-	$	1,161,931		69.18%
CMO/REMIC		466,033		14,060		-		480,093		28.58%
Municipal bonds		36,119		913		-		37,032		2.20%
Other securities		699		-		-		699		0.04%

Total available-for-sale securities	$	1,621,236	$	58,519	$	-	$	1,679,755		100.00%

Investment securities held-to-maturity:
Government agency/GSE	$	111,452	$	3,468	$	(207)	$	114,713		17.35%
Mortgage-backed securities		161,983		8,182		-		170,165		25.22%
CMO/REMIC		184,316		591		(98)		184,809		28.70%
Municipal bonds		184,504		4,054		(426)		188,132		28.73%

Total held-to-maturity securities	$	642,255	$	16,295	$	(731)	$	657,819		100.00%


	December 31, 2019
	Amortized Cost		Gross Unrealized Holding Gain		Gross Unrealized Holding Loss		Fair Value		Total Percent
	(Dollars in thousands)
Investment securities available-for-sale:
Mortgage-backed securities	$	1,185,757	$	21,306	$	(750)	$	1,206,313		69.32%
CMO/REMIC		493,214		1,392		(896)		493,710		28.37%
Municipal bonds		38,506		850		(2)		39,354		2.26%
Other securities		880		-		-		880		0.05%

Total available-for-sale securities	$	1,718,357	$	23,548	$	(1,648)	$	1,740,257		100.00%

Investment securities held-to-maturity:
Government agency/GSE	$	117,366	$	2,280	$	(657)	$	118,989		17.40%
Mortgage-backed securities		168,479		2,083		(54)		170,508		24.98%
CMO/REMIC		192,548		-		(2,458)		190,090		28.55%
Municipal bonds		196,059		3,867		(565)		199,361		29.07%

Total held-to-maturity securities	$	674,452	$	8,230	$	(3,734)	$	678,948		100.00%

The following table provides information about the amount of interest income earned on investment securities which is fully taxable and which is exempt from regular federal income tax.

	Three Months Ended March 31,
	2020		2019
	(Dollars in thousands)
Investment securities available-for-sale:
Taxable	$	9,825	$	10,309
Tax-advantaged		224		336

Total interest income from available-for-sale securities		10,049		10,645

Investment securities held-to-maturity:
Taxable		2,698		2,910
Tax-advantaged		1,300		1,615

Total interest income from held-to-maturity securities		3,998		4,525

Total interest income from investment securities	$	14,047	$	15,170

The adoption of CECL did not have a material impact on the accounting for investment securities, as approximately

90%

of the total investment securities portfolio at March 31, 2020 represents securities issued by the U.S. government or U.S. government-sponsored enterprises, with the implied guarantee of payment of principal and interest. The remaining securities are predominately AA- or better general-obligation municipal bonds. The allowance for credit losses for

held-to-maturity

investment securities under the new CECL model was zero at March 31, 2020.

We adopted ASU

2016-13

on January 1, 2020, on a

prospective

basis. Under the new guidance, once it is determined that a credit loss has occurred, an allowance for credit losses is established on our

available-for-sale

and

held-to-maturity

securities. Prior to adoption of this standard, when a decline in fair value of a debt security was determined to be other than temporary, an impairment charge for the credit component was recorded, and a new cost basis in the investment was established. During the first quarter of 2020, management determined that credit losses did not exist for securities in an unrealized loss position. As of March 31, 2020, there were no AFS investment securities with an unrealized loss position.

The tables below show the Company’s investment securities’ gross unrealized losses and fair value by investment category and length of time that individual securities have been in a continuous unrealized loss position at

December 31, 2019, prior to adoption of ASU 2016-13. Management

previously

reviewed individual securities to determine whether a decline in fair value below the amortized cost basis is other-than-temporary. The unrealized losses on these securities were primarily attributed to changes in interest rates. The issuers of these securities have not, to our knowledge, evidenced any cause for default on these securities. These securities have fluctuated in value since their purchase dates as market interest rates have fluctuated. However, we have the ability and the intention to hold these securities until their fair values recover to cost or maturity. As such, management does not deem these securities to be other-than-temporarily-impaired

	December 31, 2019
	Less Than 12 Months					12 Months or Longer					Total
	Fair Value		Gross Unrealized Holding Losses			Fair Value		Gross Unrealized Holding Losses			Fair Value		Gross Unrealized Holding Losses
	(Dollars in thousands)
Investment securities available-for-sale:
Mortgage-backed securities	$	20,289	$	(6	)	$	97,964	$	(744	)	$	118,253	$	(750	)
CMO/REMIC		177,517		(705	)		34,565		(191	)		212,082		(896	)
Municipal bonds		-		-			563		(2	)		563		(2	)

Total available-for-sale securities	$	197,806	$	(711	)	$	133,092	$	(937	)	$	330,898	$	(1,648	)

Investment securities held-to-maturity:
Government agency/GSE	$	28,359	$	(252	)	$	19,405	$	(405	)	$	47,764	$	(657	)
Mortgage-backed securities		10,411		(54	)		-		-			10,411		(54	)
CMO/REMIC		23,897		(104	)		166,193		(2,354	)		190,090		(2,458	)
Municipal bonds		7,583		(32	)		29,981		(533	)		37,564		(565	)

Total held-to-maturity securities	$	70,250	$	(442	)	$	215,579	$	(3,292	)	$	285,829	$	(3,734	)

At March 31, 2020 and December 31, 2019, investment securities having a carrying value of approximately $1.63 billion and $1.64 billion, respectively, were pledged to secure public deposits, short and long-term borrowings, and for other purposes as required or permitted by law.

The amortized cost and fair value of debt securities at March 31, 2020, by contractual maturity, are shown in the table below. Although mortgage-backed and CMO/REMIC securities have contractual maturities through 2058, expected maturities will differ from contractual maturities because borrowers may have the right to prepay such obligations without penalty. Mortgage-backed and CMO/REMIC securities are included in maturity categories based upon estimated average lives

which incorporate estimated prepayment speeds.


	March 31, 2020
	Available-for-sale				Held-to-maturity
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(Dollars in thousands)
Due in one year or less	$	13,043	$	13,160	$	768	$	788
Due after one year through five years		1,376,413		1,427,373		358,973		367,734
Due after five years through ten years		176,690		182,573		103,004		104,787
Due after ten years		55,090		56,649		179,510		184,510

Total investment securities	$	1,621,236	$	1,679,755	$	642,255	$	657,819

The investment in FHLB stock is periodically evaluated for impairment based on, among other things, the capital adequacy of the FHLB and its overall financial condition. No impairment losses have been recorded March 31, 2020.