
	At September 30, 2020
(In thousands)	Amortized Cost (1)		Unrealized Gains		Unrealized Losses		Fair Value		Allowance (2)		Net Carrying Value
Agency CMO	$	116,020	$	2,743	$	(261)	$	118,502	$	—	$	116,020
Agency MBS	2,595,711		155,221		(106)		2,750,826		—		2,595,711
Agency CMBS	2,033,826		63,401		(599)		2,096,628		—		2,033,826
Municipal bonds and notes	750,847		53,457		—		804,304		306		750,541
CMBS	227,030		9,126		—		236,156		—		227,030
Held-to-maturity securities	$	5,723,434	$	283,948	$	(966)	$	6,006,416	$	306	$	5,723,128


	At December 31, 2019
(In thousands)	Amortized Cost (1)		Unrealized Gains		Unrealized Losses		Fair Value		Allowance (2)		Net Carrying Value
Agency CMO	$	167,443	$	1,123	$	(1,200)	$	167,366	$	—	$	167,443
Agency MBS	2,957,900		60,602		(8,733)		3,009,769		—		2,957,900
Agency CMBS	1,172,491		6,444		(5,615)		1,173,320		—		1,172,491
Municipal bonds and notes	740,431		32,709		(21)		773,119		—		740,431
CMBS	255,653		2,278		(852)		257,079		—		255,653
Held-to-maturity securities	$	5,293,918	$	103,156	$	(16,421)	$	5,380,653	$	—	$	5,293,918

(1)Amortized cost excludes accrued interest receivable of $18.5 million and $21.8 million at September 30, 2020 and December 31, 2019, respectively, which is included in accrued interest and other assets in the consolidated balance sheet.

(2)The Company adopted the new accounting standard for credit losses on January 1, 2020. For periods subsequent to adoption Allowance is calculated under the CECL methodology and the resulting provision includes expected credit losses on held-to-maturity securities. The prior period did not have an allowance under applicable GAAP for that period.

Agency securities represent obligations issued by a U.S. government-sponsored enterprise or other federally-related entity and are either explicitly or implicitly guaranteed and therefore, assumed to be zero loss. Securities with unrealized losses and no allowance are considered to be of high credit quality, and therefore, no credit loss as of September 30, 2020. The current unrealized loss position of certain agency securities and non-agency CMBS with no credit loss allowance can be attributed to the changing interest rate environment. An allowance for credit losses on investment securities held-to-maturity of $397 thousand was recorded for certain Municipal bonds and notes to account for expected lifetime credit loss upon adoption of the new accounting standard for credit losses. Expected lifetime credit loss on investment securities held-to-maturity is primarily attributed to securities not rated.


	Three months ended September 30, 2020		Nine months ended September 30, 2020

(In thousands)	Municipal bonds and notes		Municipal bonds and notes
Balance beginning of period	$	309	$	—
Adoption of ASU No. 2016-13 (CECL)	—		397
Recovery of credit losses	(3)		(91)
Balance end of period	$	306	$	306

The Company monitors the credit quality of held-to-maturity debt securities through credit ratings by Standard & Poor's Rating Services (S&P), Moody's Investor Services (Moody's), Fitch Ratings, Inc., Kroll Bond Rating Agency, or DBRS Inc. Credit ratings express opinions about the credit quality of a security. Investment grade securities are rated BBB- or higher by S&P, or Baa3 or higher by Moody's, and generally considered by the rating agencies and market participants to be of low credit risk. Conversely, securities rated below investment grade, labeled as speculative grade by the rating agencies, are considered to have distinctively higher credit risk than investment grade securities. Securities shown below that are not rated are backed by U.S. Treasury obligations, and credit quality indicators are updated at each quarter end.


	Investment Grade
(In thousands)	Aaa		Aa1		Aa2		Aa3		A1		A2		A3		Baa2		Not Rated
Agency CMOs	$	—	$	116,020	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Agency MBS	—		2,595,711		—		—		—		—		—		—		—
Agency CMBS	—		2,033,826		—		—		—		—		—		—		—
Municipal bonds and notes	209,751		165,261		201,423		117,320		41,697		8,663		2,066		285		4,381
CMBS	227,030		—		—		—		—		—		—		—		—
Total held-to-maturity	$	436,781	$	4,910,818	$	201,423	$	117,320	$	41,697	$	8,663	$	2,066	$	285	$	4,381


	At September 30, 2020
(In thousands)	Amortized Cost		Fair Value
Due in one year or less	$	1,085	$	1,089
Due after one year through five years	5,340		5,611
Due after five through ten years	279,056		295,103
Due after ten years	5,437,953		5,704,613
Total held-to-maturity debt securities	$	5,723,434	$	6,006,416

For the maturity schedule above, investment securities which are not due at a single maturity date have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to repay obligations with or without prepayment penalties.


	At September 30, 2020
(In thousands)	Amortized Cost(1)		Unrealized Gains		Unrealized Losses		Fair Value(2)

Agency CMO	$	166,623	$	6,908	$	(177)	$	173,354
Agency MBS	1,446,100		81,533		(363)		1,527,270
Agency CMBS	1,024,133		27,621		—		1,051,754
CMBS	464,071		794		(9,840)		455,025
CLO	85,601		1		(1,241)		84,361
Corporate debt	14,551		—		(2,098)		12,453
Available-for-sale securities	$	3,201,079	$	116,857	$	(13,719)	$	3,304,217

	At December 31, 2019
(In thousands)	Amortized Cost(1)		Unrealized Gains		Unrealized Losses		Fair Value(2)

Agency CMO	$	184,500	$	2,218	$	(917)	$	185,801
Agency MBS	1,580,743		35,456		(4,035)		1,612,164
Agency CMBS	587,974		513		(6,935)		581,552
CMBS	432,085		38		(252)		431,871
CLO	92,628		45		(468)		92,205
Corporate debt	23,485		—		(1,245)		22,240
Available-for-sale securities	$	2,901,415	$	38,270	$	(13,852)	$	2,925,833

(1)Amortized cost excludes accrued interest receivable of $7.4 million and $8.1 million at September 30, 2020 and December 31, 2019, respectively, which is included in accrued interest and other assets in the consolidated balance sheet.

(2)Fair value represents net carrying value as there is no allowance for credit losses recorded on investment securities available-for-sale, as the securities are high credit quality, investment grade.

The following tables provide information on fair value and unrealized losses for the individual available-for-sale securities with an unrealized loss, for which an allowance for credit losses on investment securities available-for-sale has not been recorded, aggregated by classification and length of time that the individual investment securities have been in a continuous unrealized loss position:


	At September 30, 2020
	Less Than Twelve Months				Twelve Months or Longer				Total
(Dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		# of Holdings	Fair Value		Unrealized Losses

Agency CMO	$	11,358	$	(92)	$	7,935	$	(85)	3	$	19,293	$	(177)
Agency MBS	30,077		(208)		11,591		(155)		30	41,668		(363)
Agency CMBS	—		—		—		—		—	—		—
CMBS	407,322		(9,205)		22,868		(635)		38	430,190		(9,840)
CLO	65,711		(589)		18,048		(652)		4	83,759		(1,241)
Corporate debt	3,892		(371)		8,561		(1,727)		3	12,453		(2,098)
Available-for-sale in unrealized loss position	$	518,360	$	(10,465)	$	69,003	$	(3,254)	78	$	587,363	$	(13,719)


	At December 31, 2019
	Less Than Twelve Months				Twelve Months or Longer				Total
(Dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		# of Holdings	Fair Value		Unrealized Losses

Agency CMO	$	36,447	$	(352)	$	32,288	$	(565)	9	$	68,735	$	(917)
Agency MBS	41,408		(193)		299,674		(3,842)		79	341,082		(4,035)
Agency CMBS	174,406		(1,137)		357,717		(5,798)		34	532,123		(6,935)
CMBS	355,260		(232)		7,480		(20)		29	362,740		(252)
CLO	—		—		43,232		(468)		2	43,232		(468)
Corporate debt	—		—		22,240		(1,245)		4	22,240		(1,245)
Available-for-sale in unrealized loss position	$	607,521	$	(1,914)	$	762,631	$	(11,938)	157	$	1,370,152	$	(13,852)

Unrealized losses on available-for-sale debt securities presented in the previous table have not been recognized in the consolidated statements of income because the securities are high credit quality, investment grade securities that the Company does not intend to sell and will not be required to sell prior to their anticipated recovery, and the decline in fair value is primarily attributable to wider spreads in selected asset classes. Fair value is expected to recover as the securities approach maturity. As of September 30, 2020, none of the available-for-sale investment securities were in non-accrual status.


	At September 30, 2020
(In thousands)	Amortized Cost		Fair Value
Due in one year or less	$	—	$	—
Due after one year through five years	601		602
Due after five through ten years	263,579		257,909
Due after ten years	2,936,899		3,045,706
Total available-for-sale debt securities	$	3,201,079	$	3,304,217

For the nine months ended September 30, 2020, proceeds from sales of available-for-sale securities were $9.0 million, which resulted in realized gains of $8.0 thousand. There were no sales during the three months ended September 30, 2020, or the three and nine months ended September 30, 2019.

At September 30, 2020, the Company had a carrying value of $1.3 billion in callable debt securities in its CMBS, CLO, and municipal bond portfolios. The Company considers this prepayment risk in the evaluation of its interest rate risk profile.

Investment securities with a carrying value totaling $4.0 billion at September 30, 2020 and $2.7 billion at December 31, 2019 were pledged to secure public funds, trust deposits, repurchase agreements, and for other purposes, as required or permitted by law.