Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Schedule of Investments [Line Items]
Net investment income	$ 832		$ 880	$ 1,662	$ 2,470
Accrued investment income	616			616		$ 600
Limited partnership interests	7,232			7,232		8,078
Short-term investments	4,559			4,559		4,256
Fixed income securities
Schedule of Investments [Line Items]
Accrued investment income	558			558
Unrealized losses related to securities with unrealized loss position greater than or equal to 20% of cost or amortized cost	(81)			(81)
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	87.00%			87.00%
Allowance	$ (5)			$ (5)
Bank loans, net
Schedule of Investments [Line Items]
Accrued investment income	4			4
EMA limited partnerships
Schedule of Investments [Line Items]
Limited partnership interests	5,464			5,464		6,264
Limited partnership interests
Schedule of Investments [Line Items]
Limited partnership interests	1,768			1,768		1,814
Mortgage loans
Schedule of Investments [Line Items]
Loan modifications	7	$ 274
Allowance	(85)			(85)		(3)
Other investments
Schedule of Investments [Line Items]
Limited partnership interests	287			287		906
Other investments | EMA limited partnerships
Schedule of Investments [Line Items]
Limited partnership interests	287			287		902
Other investments | Limited partnership interests
Schedule of Investments [Line Items]
Limited partnership interests	$ 0			$ 0		$ 4