Bank segment - Other borrowings (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Offsetting Liabilities [Line Items]
Gross amount  of recognized  liabilities	$ 137	$ 88
Gross amount  offset in the  Balance Sheets	0	0
Net amount of liabilities presented in the Balance Sheets	137	88
Commercial account holders
Offsetting Liabilities [Line Items]
Net amount of liabilities presented in the Balance Sheets	137	88
Financial instruments	161	161
Cash collateral pledged	$ 0	$ 0