Derivative Financial Instruments - Gross and net amounts for OTC derivatives (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Asset derivatives
Asset derivatives gross amount	$ 96	$ 77
Asset derivatives, gross liability	(3)	(1)
Derivative assets net amount on balance sheet	93	76
Liability derivatives
Liability derivatives gross amount	(38)	(14)
Liability derivatives, gross asset	19	23
Net amount on balance sheet	(19)	9
OTC derivatives
Asset derivatives
Asset derivatives gross amount	30	23
Asset derivatives, gross liability	(22)	(24)
Cash collateral received	(5)	2
Derivative assets net amount on balance sheet	3	1
Derivative assets received under securities collateral	0	0
Derivative asset, fair value, amount offset against collateral	3	1
Liability derivatives
Liability derivatives gross amount	(8)	(10)
Liability derivatives, gross asset	22	24
Derivative liability offsets under cash collateral pledged	(15)	(17)
Net amount on balance sheet	(1)	(3)
Derivative liabilities received under securities collateral	0	0
Derivative liability, fair value, amount offset against collateral	$ (1)	$ (3)