Derivative Financial Instruments - Gross and net amounts for OTC derivatives (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Asset derivatives
Gross amount	$ 122	$ 121
Counter-party netting	(15)	(14)
Net amount on balance sheet	107	107
Liability derivatives
Gross amount	(6)	(12)
Counter-party netting	4	8
Net amount on balance sheet	(2)	(4)
OTC derivatives
Asset derivatives
Gross amount	10	23
Counter-party netting	(19)	(22)
Cash collateral (received) pledged	19	0
Net amount on balance sheet	10	1
Securities collateral (received) pledged	0	0
Net amount	10	1
Liability derivatives
Gross amount	(16)	(22)
Counter-party netting	19	22
Cash collateral (received) pledged	(3)	(1)
Net amount on balance sheet	0	(1)
Securities collateral (received) pledged	0	0
Net amount	$ 0	$ (1)