Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule of Investments [Line Items]
Net investment income	$ 409	$ 942	$ 830	$ 1,590
Accrued investment income	605		605		$ 600
Gross gains on fixed income securities	304	115	760	241
Gross loss on fixed income securities	(113)	$ (27)	(190)	$ (87)
Limited partnership interests	6,941		6,941		8,078
Short-term investments	5,344		5,344		4,256
Fixed income securities
Schedule of Investments [Line Items]
Accrued investment income	538		538
Unrealized losses related to securities with unrealized loss position greater than or equal to 20% of cost or amortized cost	(109)		(109)
Mortgage loans
Schedule of Investments [Line Items]
Accrued investment income	17		17
Agent loans, net
Schedule of Investments [Line Items]
Accrued investment income	$ 2		$ 2
High credit quality, percentage	86.00%		86.00%
Allowance	$ (5)		$ (5)
Bank loans, net
Schedule of Investments [Line Items]
Accrued investment income	5		5
EMA limited partnerships
Schedule of Investments [Line Items]
Limited partnership interests	5,276		5,276		6,264
Limited partnership interests
Schedule of Investments [Line Items]
Limited partnership interests	1,665		1,665		1,814
Mortgage loans
Schedule of Investments [Line Items]
Loan modifications	274
Allowance	(86)		(86)		(3)
Other investments
Schedule of Investments [Line Items]
Limited partnership interests	254		254		906
Other investments | EMA limited partnerships
Schedule of Investments [Line Items]
Limited partnership interests	251		251		902
Other investments | Limited partnership interests
Schedule of Investments [Line Items]
Limited partnership interests	$ 3		$ 3		$ 4