Derivative Financial Instruments - OTC derivatives counterparty credit exposure by counterparty credit rating (Details) $ in Millions	Sep. 30, 2022 USD ($) counter-party	Dec. 31, 2021 USD ($) counter-party
Credit Derivatives
Number of counter- parties | counter-party	5	2
Notional amount	$ 732	$ 566
Credit exposure	49	16
Exposure, net of collateral	$ 0	$ 0
A+
Credit Derivatives
Number of counter- parties | counter-party	4	1
Notional amount	$ 500	$ 199
Credit exposure	25	7
Exposure, net of collateral	$ 0	$ 0
A
Credit Derivatives
Number of counter- parties | counter-party	1	1
Notional amount	$ 232	$ 367
Credit exposure	24	9
Exposure, net of collateral	$ 0	$ 0