The Company holds various types of fixed maturity securities available-for-sale and classifies them as corporate securities (“Corporate”), Canadian and Canadian provincial government securities (“Canadian government”), Japanese government and agencies (“Japanese government”), asset-backed securities (“ABS”), commercial mortgage-backed securities (“CMBS”), residential mortgage-backed securities (“RMBS”), U.S. government and agencies (“U.S. government”), state and political subdivisions, and other foreign government, supranational and foreign government-sponsored enterprises (“Other foreign government”). ABS, CMBS, and RMBS are collectively “structured securities.”


December 31, 2023:	Amortized Cost		Allowance for Credit Losses		Unrealized Gains		Unrealized Losses		Estimated Fair Value		% of Total
Available-for-sale:
Corporate	$	42,014	$	62	$	554	$	3,751	$	38,755	64.1	%
Canadian government	3,477		—		473		33		3,917		6.5
Japanese government	3,630		—		3		502		3,131		5.2
ABS	4,661		12		19		239		4,429		7.3
CMBS	1,969		1		7		202		1,773		2.9
RMBS	1,173		—		8		102		1,079		1.8
U.S. government	2,725		—		9		214		2,520		4.2
State and political subdivisions	1,236		—		7		129		1,114		1.8
Other foreign government	4,092		—		45		388		3,749		6.2
Total fixed maturity securities	$	64,977	$	75	$	1,125	$	5,560	$	60,467	100.0	%


December 31, 2022:	Amortized Cost		Allowance for Credit Losses		Unrealized Gains		Unrealized Losses		Estimated Fair Value		% of Total
Available-for-sale:
Corporate	$	38,963	$	27	$	168	$	5,135	$	33,969	64.2	%
Canadian government	3,311		—		381		66		3,626		6.9
Japanese government	3,033		—		4		478		2,559		4.8
ABS	4,324		10		4		440		3,878		7.3
CMBS	1,835		—		—		212		1,623		3.1
RMBS	1,054		—		1		114		941		1.8
U.S. government	1,690		—		4		212		1,482		2.8
State and political subdivisions	1,282		—		10		173		1,119		2.1
Other foreign government	4,171		—		22		489		3,704		7.0
Total fixed maturity securities	$	59,663	$	37	$	594	$	7,319	$	52,901	100.0	%

The Company enters into various collateral arrangements with counterparties that require both the pledging and acceptance of fixed maturity securities as collateral. Pledged fixed maturity securities are included in fixed maturity securities, available-for-sale in the consolidated balance sheets. Fixed maturity securities received as collateral are held in separate custodial accounts and are not recorded on the Company’s consolidated balance sheets. Subject to certain constraints, the Company is permitted by contract to sell or repledge collateral it receives; however, as of December 31, 2023 and 2022, none of the collateral received had been sold or repledged. The Company also holds assets in trust to satisfy collateral requirements under derivative transactions and certain third-party reinsurance treaties. The following table includes fixed maturity securities pledged and received as collateral and assets in trust held to satisfy collateral requirements under derivative transactions and certain third-party reinsurance treaties as of December 31, 2023 and 2022 (dollars in millions):


	2023				2022
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Fixed maturity securities pledged as collateral	$	572	$	517	$	355	$	292
Fixed maturity securities received as collateral	n/a		1,827		n/a		1,428
Assets in trust held to satisfy collateral requirements	32,758		30,359		31,510		27,817

The Company monitors its concentrations of financial instruments on an ongoing basis and mitigates credit risk by maintaining a diversified investment portfolio that limits exposure to any one issuer. The Company’s exposure to concentrations of credit risk from single issuers greater than 10% of the Company’s equity included securities of the U.S. government and its agencies and the Japanese government and its agencies, as well as the securities disclosed below, as of December 31, 2023 and 2022 (dollars in millions):


	2023				2022
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Fixed maturity securities guaranteed or issued by:

Canadian province of Quebec	$	1,467	$	1,748	$	1,436	$	1,649
Canadian province of Ontario	1,019		1,125		982		1,068

The amortized cost and estimated fair value of fixed maturity securities classified as available-for-sale as of December 31, 2023, are shown by contractual maturity in the table below (dollars in millions). Actual maturities can differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Structured securities are shown separately in the table below as they are not due at a single maturity date.


	Amortized Cost		Estimated Fair Value
Available-for-sale:
Due in one year or less	$	1,587	$	1,595
Due after one year through five years	11,517		11,294
Due after five years through ten years	11,224		10,637
Due after ten years	32,846		29,660
Structured securities	7,803		7,281
Total	$	64,977	$	60,467


December 31, 2023:	Amortized Cost		Estimated Fair Value		% of Total
Finance	$	15,052	$	13,789	35.6	%
Industrial	21,413		19,935		51.4
Utility	5,549		5,031		13.0
Total	$	42,014	$	38,755	100.0	%

December 31, 2022:	Amortized Cost		Estimated Fair Value		% of Total
Finance	$	14,551	$	12,680	37.3	%
Industrial	19,624		17,257		50.8
Utility	4,788		4,032		11.9
Total	$	38,963	$	33,969	100.0	%

As discussed in Note 2 – “Significant Accounting Policies and Pronouncements,” allowances for credit losses on fixed maturity securities are recognized in investment related gains (losses), net. The amount recognized represents the difference between the amortized cost of the security and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the fixed maturity security prior to the allowance for credit losses. Any remaining difference between the fair value and amortized cost is recognized in OCI.


	Corporate		ABS		CMBS		Other Foreign Government		Total
Year ended December 31, 2023:
Balance, beginning of period	$	27	$	10	$	—	$	—	$	37
Credit losses recognized on securities for which credit losses were not previously recorded	51		—		1		—		52
Reductions for securities sold during the period	(10)		—		—		—		(10)
Reductions for securities the Company intends to sell or more likely than not will be required to sell before recovery of its amortized cost	—		—		—		—		—
Additional increases or decreases for credit losses on securities that had an allowance recorded in a previous period	—		2		—		—		2
Write-offs charged against the allowance	(6)		—		—		—		(6)
Balance, end of period	$	62	$	12	$	1	$	—	$	75


	Corporate		ABS		CMBS		Other Foreign Government		Total
Year ended December 31, 2022:
Balance, beginning of period	$	26	$	—	$	1	$	4	$	31
Credit losses recognized on securities for which credit losses were not previously recorded	31		10		—		1		42
Reductions for securities sold during the period	(32)		—		—		(7)		(39)
Reductions for securities the Company intends to sell or more likely than not will be required to sell before recovery of its amortized cost	(4)		—		—		—		(4)
Additional increases or decreases for credit losses on securities that had an allowance recorded in a previous period	6		—		(1)		2		7
Write-offs charged against the allowance	—		—		—		—		—
Balance, end of period	$	27	$	10	$	—	$	—	$	37

The Company’s determination of whether a decline in value necessitates the recording of an allowance for credit losses includes an analysis of whether the issuer is current on its contractual payments, evaluating whether it is probable that the Company will

The following tables present the estimated fair value and gross unrealized losses for the 5,788 and 6,441 fixed maturity securities for which an allowance for credit loss has not been recorded as of December 31, 2023 and December 31, 2022, and the estimated fair value had declined and remained below amortized cost (dollars in millions). These investments are presented by class and grade of security, as well as the length of time the related fair value has continuously remained below amortized cost.


	Less than 12 months				12 months or greater				Total
December 31, 2023:	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
Investment grade securities:
Corporate	$	2,134	$	70	$	24,207	$	3,524	$	26,341	$	3,594
Canadian government	—		—		459		33		459		33
Japanese government	876		50		2,193		452		3,069		502
ABS	336		5		3,025		223		3,361		228
CMBS	160		5		1,328		190		1,488		195
RMBS	115		3		681		99		796		102
U.S. government	614		10		717		204		1,331		214
State and political subdivisions	73		1		864		128		937		129
Other foreign government	254		3		2,290		333		2,544		336
Total investment grade securities	4,562		147		35,764		5,186		40,326		5,333
Below investment grade securities:
Corporate	295		36		649		121		944		157


ABS	—		—		68		10		68		10
CMBS	—		—		4		1		4		1

Other foreign government	—		—		193		52		193		52
Total below investment grade securities	295		36		914		184		1,209		220
Total fixed maturity securities	$	4,857	$	183	$	36,678	$	5,370	$	41,535	$	5,553


	Less than 12 months				12 months or greater				Total
December 31, 2022:	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
Investment grade securities:
Corporate	$	21,867	$	2,756	$	6,840	$	2,225	$	28,707	$	4,981
Canadian government	554		42		71		23		625		65
Japanese government	815		86		1,694		392		2,509		478
ABS	1,596		153		1,931		269		3,527		422
CMBS	1,314		144		281		65		1,595		209
RMBS	664		62		181		53		845		115
U.S. government	1,202		64		253		148		1,455		212
State and political subdivisions	819		124		131		50		950		174
Other foreign government	1,942		167		1,026		260		2,968		427
Total investment grade securities	30,773		3,598		12,408		3,485		43,181		7,083
Below investment grade securities:
Corporate	767		87		305		61		1,072		148


ABS	52		6		38		9		90		15
CMBS	—		—		—		—		—		—

Other foreign government	39		2		164		60		203		62
Total below investment grade securities	858		95		507		130		1,365		225
Total fixed maturity securities	$	31,631	$	3,693	$	12,915	$	3,615	$	44,546	$	7,308

The Company did not intend to sell, and more likely than not would not be required to sell, the securities outlined in the tables above, as of the dates indicated. However, unforeseen facts and circumstances may cause the Company to sell fixed maturity securities in the ordinary course of managing its portfolio to meet certain diversification, credit quality and liquidity guidelines. Changes in unrealized losses are primarily driven by changes in risk-free interest rates and credit spreads.


	For the years ended December 31,
	2023		2022		2021
Fixed maturity securities available-for-sale	$	2,753	$	2,305	$	2,059
Equity securities	6		6		5
Mortgage loans	324		298		293
Policy loans	54		54		55
Funds withheld at interest	317		253		351
Limited partnerships and real estate joint ventures	181		331		419
Short-term investments and cash and cash equivalents	99		29		3
Other invested assets	21		12		61
Investment income	3,755		3,288		3,246
Investment expense	(164)		(127)		(108)
Net investment income	$	3,591	$	3,161	$	3,138

As of December 31, 2023, the Company held non-income producing securities with amortized costs, net of allowances, of $88 million and estimated fair values of $46 million. As of December 31, 2022, the Company held non-income producing securities with amortized costs, net of allowances, of $87 million and estimated fair values of $45 million. Generally, securities are non-income producing when principal or interest is not paid primarily as a result of bankruptcies or credit defaults.


	For the years ended December 31,
	2023		2022		2021
Fixed maturity securities available-for-sale:
Change in allowance for credit losses	$	(38)	$	(6)	$	(11)
Impairments on fixed maturity securities	(3)		(17)		(1)
Realized gains on investment activity	72		192		299
Realized losses on investment activity	(275)		(396)		(65)
Net gains (losses) on equity securities	(1)		(21)		25
Change in mortgage loan allowance for credit losses	(16)		(16)		29
Change in fair value of certain limited partnership investments	48		38		169

Net losses on free-standing derivatives	(129)		(166)		(10)
Net gains (losses) on embedded derivatives	(163)		(173)		107
Other, net	24		26		25
Total investment related gains (losses), net	$	(481)	$	(539)	$	567


	2023				2022
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Securities borrowing transactions:
Securities borrowed (1)	n/a		$	947	n/a		$	852
Securities pledged as collateral (2)	$	845	676		$	859	693
Securities lending transactions:
Securities loaned (2)	60		56		59		55
Securities received as collateral (3)	n/a		66		n/a		66
Repurchase/reverse repurchase transactions:
Securities sold (2)	1,486		1,333		898		779

Securities purchased (3)	n/a		517		n/a		619
Cash received (4)	820		820		149		149

(1)Securities borrowed are not reflected on the consolidated balance sheets. Collateral associated with certain borrowed securities is not included within this table as the collateral pledged to the counterparty is the right to reinsurance treaty cash flows.


	December 31, 2023
	Remaining Contractual Maturity of the Agreements
	Overnight and Continuous		Up to 30 Days		30 – 90 Days		Greater than 90 Days		Total
Securities lending transactions:
Corporate	$	—	$	—	$	—	$	40	$	40

State and political subdivisions	—		—		—		11		11
Other foreign government	—		—		—		5		5
Total	—		—		—		56		56
Repurchase/reverse repurchase transactions:
Corporate	—		—		—		553		553
Japanese government	—		—		—		158		158
ABS	—		—		—		229		229
CMBS	—		—		—		221		221


RMBS	—		—		—		52		52
U.S. government and agencies	—		—		—		14		14
Other foreign government	—		—		—		106		106



Total	—		—		—		1,333		1,333
Total transactions	$	—	$	—	$	—	$	1,389	$	1,389


	December 31, 2022
	Remaining Contractual Maturity of the Agreements
	Overnight and Continuous		Up to 30 Days		30 – 90 Days		Greater than 90 Days		Total
Securities lending transactions:
Corporate	$	—	$	—	$	—	$	42	$	42
Canadian government	—		—		—		5		5
State and political subdivisions	—		—		—		3		3
Other foreign government	—		—		—		5		5
Total	—		—		—		55		55
Repurchase/reverse repurchase transactions:
Corporate	—		—		—		279		279
Japanese government	—		—		—		278		278
ABS	—		—		—		54		54
CMBS	—		—		—		63		63
RMBS	—		—		—		10		10

Other foreign government	—		—		—		95		95






Total	—		—		—		779		779
Total transactions	$	—	$	—	$	—	$	834	$	834

As of December 31, 2023, mortgage loans were geographically dispersed throughout the U.S. with the largest concentrations in California (13.4%), Texas (11.0%) and Washington (7.5%), in addition to loans secured by properties in Canada (4.0%) and the United Kingdom (2.4%). The recorded investment in mortgage loans presented below is gross of unamortized deferred loan origination fees and expenses, and allowance for credit losses.


	2023				2022
	Carrying Value		% of Total		Carrying Value		% of Total
Property type:
Office	$	1,700	22.8	%	$	1,706	25.6	%
Retail	2,437		32.7		2,290		34.4
Industrial	1,947		26.1		1,518		22.8
Apartment	913		12.2		763		11.5
Hotel	413		5.5		319		4.8
Other commercial	49		0.7		57		0.9
Recorded investment	7,459		100.0	%	6,653		100.0	%
Unamortized balance of loan origination fees and expenses	(15)				(12)
Allowance for credit losses	(67)				(51)
Total mortgage loans	$	7,377			$	6,590


	2023				2022
	Recorded Investment		% of Total		Recorded Investment		% of Total
Due within five years	$	3,228	43.3	%	$	2,652	39.9	%
Due after five years through ten years	3,334		44.7		2,930		44.0
Due after ten years	897		12.0		1,071		16.1
Total	$	7,459	100.0	%	$	6,653	100.0	%


	Recorded Investment
	Debt Service Ratios						Construction loans
	>1.20x		1.00x – 1.20x		<1.00x				Total		% of Total
December 31, 2023:
Loan-to-Value Ratio
0% – 59.99%	$	3,672	$	272	$	27	$	46	$	4,017	53.9	%
60% – 69.99%	1,947		154		44		—		2,145		28.8
70% – 79.99%	843		52		34		—		929		12.4
80% or greater	198		70		100		—		368		4.9
Total	$	6,660	$	548	$	205	$	46	$	7,459	100.0	%


	Recorded Investment
	Debt Service Ratios						Construction loans
	>1.20x		1.00x – 1.20x		<1.00x				Total		% of Total
December 31, 2022:
Loan-to-Value Ratio
0% – 59.99%	$	3,466	$	215	$	56	$	18	$	3,755	56.4	%
60% – 69.99%	1,894		119		71		—		2,084		31.3
70% – 79.99%	475		49		91		—		615		9.3
80% or greater	81		—		118		—		199		3.0
Total	$	5,916	$	383	$	336	$	18	$	6,653	100.0	%


	Recorded Investment
	Year of Origination
December 31, 2023:	2023		2022		2021		2020		2019		Prior		Total
Internal credit quality grade:
High investment grade	$	475	$	635	$	573	$	304	$	491	$	1,734	$	4,212
Investment grade	754		668		384		245		313		564		2,928
Average	12		—		—		18		63		203		296
Watch list	—		—		—		—		—		16		16
In or near default	—		—		—		—		—		7		7
Total	$	1,241	$	1,303	$	957	$	567	$	867	$	2,524	$	7,459


	Recorded Investment
	Year of Origination
December 31, 2022:	2022		2021		2020		2019		2018		Prior		Total
Internal credit quality grade:
High investment grade	$	698	$	684	$	327	$	561	$	422	$	1,565	$	4,257
Investment grade	586		284		248		279		252		531		2,180
Average	—		6		—		39		52		83		180
Watch list	—		—		—		—		—		—		—
In or near default	—		—		—		—		—		36		36
Total	$	1,284	$	974	$	575	$	879	$	726	$	2,215	$	6,653

During 2023, the Company modified ten mortgage loans for borrowers experiencing financial difficulty providing interest only payments and maturity extensions, two of which were paid in full as of December 31, 2023. The total recorded investment before allowance for credit losses for the remaining modified loans was $92 million as of December 31, 2023. During 2022, the company modified three mortgage loans to interest only payments, one of which was paid in full as of December 31, 2022. During 2022, the total recorded investment before allowance for credit losses for mortgage loans that were modified and met the criteria of Troubled Debt Restructuring (“TDR”) was $67 million. During 2021, the Company did not have any significant loans that were modified and met the criteria of a TDR.

The Company had one mortgage loan in the amount of $7 million on nonaccrual status as of December 31, 2023. The Company had two mortgage loans in the amount of $36 million that were on nonaccrual status as of December 31, 2022. During 2023, the Company converted three mortgage loans totaling $62 million at the time of foreclosure to owned properties as a result of foreclosures. The Company did not acquire any impaired mortgage loans during 2023, 2022 and 2021.

The majority of policy loans are associated with one client. These policy loans present no credit risk as the amount of the loan cannot exceed the obligation due to the ceding company upon the death of the insured or surrender of the underlying policy. The provisions of the treaties in force and the underlying policies determine the policy loan interest rates. The Company earns a spread between the interest rate earned on policy loans and the interest rate credited to corresponding liabilities.

As of December 31, 2023, $3.3 billion of the funds withheld at interest balance is primarily associated with two clients. For reinsurance agreements written on a modco basis and certain agreements written on a coinsurance funds withheld basis, assets equal to the net statutory reserves are withheld and legally owned and managed by the ceding company and are reflected as funds withheld at interest. In the event of a ceding company’s insolvency, the Company would need to assert a claim on the assets supporting its reserve liabilities. However, the risk of loss to the Company is mitigated by its ability to offset amounts it owes the ceding company for claims or allowances against amounts owed to the Company from the ceding company.


	2023		2022
Limited partnerships – equity method	$	925	$	934
Limited partnerships – fair value	856		683
Limited partnerships – cost method	71		49
Real estate joint ventures	783		661
Total limited partnerships and real estate joint ventures	$	2,635	$	2,327

Other invested assets include lifetime mortgages and derivative contracts. Other invested assets also includes FHLB common stock and real estate held for investment, which are included in “Other” in the table below. As of December 31, 2023 and 2022, the allowance for credit losses for lifetime mortgages was not material. The carrying values of other invested assets as of December 31, 2023 and 2022 are as follows (dollars in millions):