Derivatives - Credit Risk Assumed through Credit Derivatives (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Credit Derivatives [Line Items]
Derivative, Notional Amount	$ 11,224	$ 12,129
Fair Value	(42)	(61)
Credit derivatives
Credit Derivatives [Line Items]
Derivative, Notional Amount	105	784
Fair Value	(2)	18
Offsetting Notional Amount	105	109
Offsetting Fair Value	2	3
Credit derivatives | Single name credit default swaps | A Minus | Investment grade risk exposure
Credit Derivatives [Line Items]
Derivative, Notional Amount		175
Fair Value		$ 9
Weighted Average Years to Maturity		5 years
Offsetting Notional Amount		$ 0
Offsetting Fair Value		0
Credit derivatives | Basket credit default swaps | BBB Plus | Investment grade risk exposure
Credit Derivatives [Line Items]
Derivative, Notional Amount		500
Fair Value		$ 12
Weighted Average Years to Maturity		5 years
Offsetting Notional Amount		$ 0
Offsetting Fair Value		0
Credit derivatives | Basket credit default swaps | Standard & Poor's, AAA Rating [Member] | Investment grade risk exposure
Credit Derivatives [Line Items]
Derivative, Notional Amount	101	100
Fair Value	$ 0	$ 1
Weighted Average Years to Maturity	6 years	8 years
Offsetting Notional Amount	$ 101	$ 100
Offsetting Fair Value	0	(1)
Credit derivatives | Basket credit default swaps | Standard & Poor's, CCC+ Rating | Below investment grade risk exposure
Credit Derivatives [Line Items]
Derivative, Notional Amount		9
Fair Value		$ (4)
Average Term of Credit Risk Derivatives Less than 1 Year		Less than 1 year
Offsetting Notional Amount		$ 9
Offsetting Fair Value		$ 4
Credit derivatives | Basket credit default swaps | CCC | Below investment grade risk exposure
Credit Derivatives [Line Items]
Derivative, Notional Amount	4
Fair Value	$ (2)
Average Term of Credit Risk Derivatives Less than 1 Year	Less than 1 year
Offsetting Notional Amount	$ 4
Offsetting Fair Value	$ 2