Investments (Tables)

12 Months Ended

Dec. 31, 2020

Investments [Abstract]

Available-for-sale Securities [Table Text Block]

The following tables provide information relating to investments in fixed maturity securities by type as of December 31, 2020 and 2019 (dollars in millions):

December 31, 2020:	Amortized Cost		Allowance for Credit Losses		Unrealized Gains		Unrealized Losses		Estimated Fair Value		% of Total
Available-for-sale:
Corporate	$	31,963	$	17	$	4,356	$	94	$	36,208	63.9	%
Canadian government	3,145		—		1,995		—		5,140		9.1
RMBS	1,735		—		84		2		1,817		3.2
ABS	3,099		—		35		42		3,092		5.4
CMBS	1,790		3		102		21		1,868		3.3
U.S. government	1,242		—		196		1		1,437		2.5
State and political subdivisions	1,237		—		157		4		1,390		2.4
Other foreign government	5,337		—		479		33		5,783		10.2
Total fixed maturity securities	$	49,548	$	20	$	7,404	$	197	$	56,735	100.0	%

December 31, 2019:	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value		% of Total
Available-for-sale:
Corporate	$	29,205	$	2,269	$	81	$	31,393	61.4	%
Canadian government	3,016		1,596		—		4,612		9.0
RMBS	2,339		62		3		2,398		4.7
ABS	2,973		19		14		2,978		5.8
CMBS	1,841		61		3		1,899		3.7
U.S. government	2,096		57		1		2,152		4.2
State and political subdivisions	1,074		93		3		1,164		2.3
Other foreign government	4,209		321		5		4,525		8.9
Total fixed maturity securities	$	46,753	$	4,478	$	110	$	51,121	100.0	%

Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block]

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, 2020 and 2019 (dollars in millions):

	2020				2019
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Fixed maturity securities pledged as collateral	$	148	$	162	$	113	$	116
Fixed maturity securities received as collateral	n/a		1,784		n/a		727
Assets in trust held to satisfy collateral requirements	27,675		31,179		27,290		29,239

Concentration Risk Disclosure [Text Block]

The Company’s exposure to concentrations of credit risk from single issuers greater than 10% of the Company’s stockholders’ equity included securities of the U.S. government and its agencies, as well as the securities disclosed below, as of December 31, 2020 and 2019 (dollars in millions):

	2020				2019
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Fixed maturity securities guaranteed or issued by:
Government of Japan	$	1,493	$	1,491	$	813	$	852
Canadian province of Quebec	1,303		2,474		1,205		2,163
Canadian province of Ontario	1,054		1,528		1,014		1,379

Investments Classified By Contractual Maturity Date [Table Text Block]

The amortized cost and estimated fair value of fixed maturity securities classified as available-for-sale as of December 31, 2020, 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	$	1,351	$	1,362
Due after one year through five years	8,248		8,797
Due after five years through ten years	10,676		11,956
Due after ten years	22,649		27,843
Structured securities	6,624		6,777
Total	$	49,548	$	56,735

Fixed Maturity Holdings Industry Types [Table Text Block]

The tables below show the major sectors of the Company’s corporate fixed maturity holdings as of December 31, 2020 and 2019 (dollars in millions):

December 31, 2020:	Amortized Cost		Estimated Fair Value		% of Total
Finance	$	11,785	$	13,236	36.6	%
Industrial	16,274		18,435		50.9
Utility	3,904		4,537		12.5
Total	$	31,963	$	36,208	100.0	%
December 31, 2019:	Amortized Cost		Estimated Fair Value		% of Total
Finance	$	10,896	$	11,653	37.2	%
Industrial	14,692		15,803		50.3
Utility	3,617		3,937		12.5
Total	$	29,205	$	31,393	100.0	%

Roll Forward Of Cumulative Credit Loss Component Of Otti Income Loss [Table Text Block]

	Corporate		CMBS		Other Foreign Government		Total
Balance, beginning of period	$	—	$	—	$	—	$	—
Credit losses recognized on securities for which credit losses were not previously recorded	36		3		2		41
Reductions for securities sold during the period	(19)		—		(2)		(21)
Balance, end of period	$	17	$	3	$	—	$	20

Investments In Debt And Equity Securities Gross Unrealized Losses Disclosures [Table Text Block]

The following table presents the total gross unrealized losses for the 877 and 1,072 fixed maturity securities as of December 31, 2020 and 2019, where the estimated fair value had declined and remained below amortized cost by the indicated amount (dollars in millions):

	2020				2019
	Gross Unrealized Losses		% of Total		Gross Unrealized Losses		% of Total
Less than 20%	$	133	67.5	%	$	76	69.1	%
20% or more for less than six months	42		21.3		20		18.2
20% or more for six months or greater	22		11.2		14		12.7
Total	$	197	100.0	%	$	110	100.0	%

Fair Value And Investments In Debt And Equity Securities Disclosures [Table Text Block]

The following tables present the estimated fair values and gross unrealized losses for fixed maturity securities that have estimated fair values below amortized cost as of December 31, 2020 and 2019 (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 remained below amortized cost.

	Less than 12 months				12 months or greater				Total
December 31, 2020:	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
Investment grade securities:
Corporate	$	930	$	29	$	70	$	5	$	1,000	$	34
RMBS	294		2		—		—		294		2
ABS	1,096		17		570		11		1,666		28
CMBS	160		6		—		—		160		6
U.S. government	27		1		—		—		27		1
State and political subdivisions	66		1		16		3		82		4
Other foreign government	973		27		—		—		973		27
Total investment grade securities	3,546		83		656		19		4,202		102
Below investment grade securities:
Corporate	375		49		81		11		456		60
ABS	20		13		4		1		24		14
CMBS	91		15		—		—		91		15
Other foreign government	36		3		28		3		64		6
Total below investment grade securities	522		80		113		15		635		95
Total fixed maturity securities	$	4,068	$	163	$	769	$	34	$	4,837	$	197

	Less than 12 months				12 months or greater				Total
December 31, 2019:	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
Investment grade securities:
Corporate	$	1,936	$	29	$	293	$	7	$	2,229	$	36
RMBS	367		2		84		1		451		3
ABS	773		5		739		9		1,512		14
CMBS	253		3		—		—		253		3
U.S. government	49		1		—		—		49		1
State and political subdivisions	103		2		12		1		115		3
Other foreign government	278		4		—		—		278		4
Total investment grade securities	3,759		46		1,128		18		4,887		64
Below investment grade securities:
Corporate	220		38		100		7		320		45
ABS	—		—		—		—		—		—
CMBS	—		—		—		—		—		—
Other foreign government	—		—		10		1		10		1
Total below investment grade securities	220		38		110		8		330		46
Total fixed maturity securities	$	3,979	$	84	$	1,238	$	26	$	5,217	$	110

Investment Income [Table Text Block]

Major categories of investment income, net of related expenses, consist of the following (dollars in millions):

	2020		2019		2018
Fixed maturity securities available-for-sale	$	1,928	$	1,786	$	1,529
Equity securities	6		8		4
Mortgage loans on real estate	282		255		214
Policy loans	56		58		59
Funds withheld at interest	279		297		310
Short-term investments and cash and cash equivalents	7		28		14
Other invested assets	109		184		99
Investment income	2,667		2,616		2,229
Investment expense	(92)		(96)		(90)
Investment income, net of related expenses	$	2,575	$	2,520	$	2,139

Gain (Loss) on Securities [Table Text Block]

Investment related gains (losses), net, consist of the following (dollars in millions):

	2020		2019		2018
Fixed maturity securities available for sale:
Impairments and change in allowance for credit losses	$	(21)	$	(31)	$	(28)
Gain on investment activity	114		151		65
Loss on investment activity	(82)		(50)		(159)
Net gains (losses) on equity securities	(15)		16		(20)
Other impairment losses and change in mortgage loan provision	(56)		(12)		(12)
Derivatives and other, net	27		17		(16)
Total investment related gains (losses), net	$	(33)	$	91	$	(170)

Schedule of Repurchase Agreements [Table Text Block]

The following table includes the amount of borrowed securities, loaned securities, and securities received as collateral as part of the securities lending program, and repurchased/reverse repurchased securities pledged and received as of December 31, 2020 and 2019 (dollars in millions):

	2020				2019
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Borrowed securities	$	118	$	161	$	339	$	369
Securities lending:
Securities loaned	94		105		98		104
Securities received	n/a		102		n/a		107
Repurchase program/reverse repurchase program:
Securities pledged	653		711		356		384
Securities received	n/a		669		n/a		370

Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets [Table Text Block]

The following tables present information on the Company’s securities lending and repurchase/reverse repurchase transactions as of December 31, 2020 and 2019, respectively (dollars in millions). Collateral associated with certain borrowed securities is not included within the tables as the collateral pledged to each counterparty is the right to reinsurance treaty cash flows.

	December 31, 2020
	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	$	—	$	—	$	—	$	105	$	105
Total	—		—		—		105		105
Repurchase/reverse repurchase transactions:
Corporate	—		—		—		417		417
Other foreign government	—		—		—		294		294
Total	—		—		—		711		711
Total transactions	$	—	$	—	$	—	$	816	$	816
Gross amount of recognized liabilities for securities lending and repurchase/reverse repurchase transactions in preceding table									$	771
Amounts related to agreements not included in offsetting disclosure									$	45

	December 31, 2019
	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	$	—	$	—	$	—	$	104	$	104
Total	—		—		—		104		104
Repurchase/reverse repurchase transactions:
Corporate	—		—		—		286		$	286
Other foreign government	—		—		—		98		98
Total	—		—		—		384		384
Total transactions	$	—	$	—	$	—	$	488	$	488
Gross amount of recognized liabilities for securities lending and repurchase/reverse repurchase transactions in preceding table									$	478
Amounts related to agreements not included in offsetting disclosure									$	10

Disclosure Of Real Estate Holdings By Property Type [Table Text Block]

The recorded investment in mortgage loans on real estate presented below is gross of unamortized deferred loan origination fees and expenses, and valuation allowances.

The following table presents the distribution of the Company’s recorded investment in mortgage loans by property type as of December 31, 2020 and 2019 (dollars in millions):

	2020				2019
	Carrying Value		Percentage of Total		Carrying Value		Percentage of Total
Property type:
Office	$	1,702	29.0	%	$	1,771	31.0	%
Retail	1,711		29.3		1,686		29.4
Industrial	1,210		20.6		1,169		20.4
Apartment	808		13.8		766		13.4
Other commercial	430		7.3		335		5.8
Recorded investment	5,861		100.0	%	5,727		100.0	%
Unamortized balance of loan origination fees and expenses	(10)				(9)
Valuation allowances	(64)				(12)
Total mortgage loans on real estate	$	5,787			$	5,706

Disclosure of Real Estate Holdings Classified By Contractual Maturity Date [Table Text Block]

The following table presents the maturities of the Company’s recorded investment in mortgage loans as of December 31, 2020 and 2019 (dollars in millions):

	2020				2019
	Recorded Investment		% of Total		Recorded Investment		% of Total
Due within five years	$	2,276	38.8	%	$	1,841	32.2	%
Due after five years through ten years	2,768		47.3		2,944		51.4
Due after ten years	817		13.9		942		16.4
Total	$	5,861	100.0	%	$	5,727	100.0	%

Accounts Receivable, Noncurrent, Credit Quality Indicator

The following tables set forth certain key credit quality indicators of the Company’s recorded investment in mortgage loans as of December 31, 2020 and 2019 (dollars in millions):

	Recorded Investment
	Debt Service Ratios						Construction loans
	>1.20x		1.00x - 1.20x		<1.00x				Total		% of Total
December 31, 2020:
Loan-to-Value Ratio
0% - 59.99%	$	2,774	$	106	$	17	$	12	$	2,909	49.6	%
60% - 69.99%	2,013		62		33		—		2,108		36.0
70% - 79.99%	555		49		13		—		617		10.5
80% or greater	189		21		17		—		227		3.9
Total	$	5,531	$	238	$	80	$	12	$	5,861	100.0	%

	Recorded Investment
	Debt Service Ratios						Construction loans
	>1.20x		1.00x - 1.20x		<1.00x				Total		% of Total
December 31, 2019:
Loan-to-Value Ratio
0% - 59.99%	$	3,025	$	52	$	7	$	—	$	3,084	53.8	%
60% - 69.99%	1,841		53		11		—		1,905		33.3
70% - 79.99%	492		13		39		—		544		9.5
80% or greater	96		61		37		—		194		3.4
Total	$	5,454	$	179	$	94	$	—	$	5,727	100.0	%

Financing Receivable Credit Quality Indicators [Table Text Block]

The following table sets forth credit quality grades by year of origination of the Company’s recorded investment in mortgage loans as of December 31, 2020 (dollars in millions):

	Recorded Investment
	Year of Origination
December 31, 2020:	2020		2019		2018		2017		2016		Prior		Total
Internal credit quality grade:
High investment grade	$	411	$	616	$	493	$	336	$	574	$	1,008	$	3,438
Investment grade	352		496		399		407		249		368		2,271
Average	—		—		—		19		37		55		111
Watch list	—		—		—		—		—		4		4
In or near default	—		—		—		—		—		37		37
Total	$	763	$	1,112	$	892	$	762	$	860	$	1,472	$	5,861

Financing Receivable, Past Due

The following table presents the current and past due composition of the Company’s recorded investment in mortgage loans as of December 31, 2020 and 2019 (dollars in millions):

	2020		2019
31-60 days past due	$	15	$	—
Total past due	15		—
Current	5,846		5,727
Total	$	5,861	$	5,727

Recorded Investment And Allowance For Credit Losses [Table Text Block]

The following table presents the recorded investment in mortgage loans, by method of measuring impairment, and the related valuation allowances, as of December 31, 2020 and 2019 (dollars in millions):

	2020		2019
Mortgage loans:
Individually measured for impairment	$	37	$	17
Collectively measured for impairment	5,824		5,710
Recorded investment	$	5,861	$	5,727
Valuation allowances:
Individually measured for impairment	$	—	$	—
Collectively measured for impairment	64		12
Total valuation allowances	$	64	$	12

Allowance For Loan And Lease Losses Provision For Loss Net [Table Text Block]

The following table presents information regarding the Company’s loan valuation allowances for mortgage loans as of December 31, 2020, 2019 and 2018 (dollars in millions):

	2020		2019		2018
Balance, beginning of period	$	12	$	11	$	9
Adoption of new accounting standard	14		—		—
Provision	38		1		2
Balance, end of period	$	64	$	12	$	11

Impaired Financing Receivables [Table Text Block]

The following table presents information regarding the portion of the Company’s mortgage loans that were impaired as of December 31, 2020 and 2019 (dollars in millions):

	Unpaid Principal Balance		Recorded Investment		Related Allowance		Carrying Value
December 31, 2020:
Impaired mortgage loans with no valuation allowance recorded	$	37	$	37	$	—	$	37
Impaired mortgage loans with valuation allowance recorded	—		—		—		—
Total impaired mortgage loans	$	37	$	37	$	—	$	37
December 31, 2019:
Impaired mortgage loans with no valuation allowance recorded	$	17	$	17	$	—	$	17
Impaired mortgage loans with valuation allowance recorded	—		—		—		—
Total impaired mortgage loans	$	17	$	17	$	—	$	17

The following table presents the Company’s average investment balance of impaired mortgage loans and the related interest income for the years ended December 31, 2020, 2019 and 2018 (dollars in millions):

	2020				2019				2018
	Average Investment(1)		Interest Income		Average Investment(1)		Interest Income		Average Investment(1)		Interest Income
Impaired mortgage loans with no valuation allowance recorded	$	25	$	1	$	20	$	1	$	24	$	1
Impaired mortgage loans with valuation allowance recorded	—		—		—		—		—		—
Total	$	25	$	1	$	20	$	1	$	24	$	1

(1)Average recorded investment represents the average loan balances as of the beginning of period and all subsequent quarterly end of period balances.

Schedule of Other Assets [Table Text Block]

Carrying values of these assets as of December 31, 2020 and 2019 are as follows (dollars in millions):

	2020		2019
Limited partnership interests and real estate joint ventures	$	1,367	$	1,134
Lifetime mortgages	935		775
Derivatives	140		117
FVO contractholder-directed unit-linked investments	289		260
Other	98		77
Total other invested assets	$	2,829	$	2,363