Leases - Operating ROU Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease ROU assets	$ 181	$ 527
Operating lease liabilities	$ 305	$ 625
Weighted-average remaining lease term	6 years 8 months 12 days	6 years 9 months 18 days
Weighted-average discount rate (percent)	3.00%	3.00%
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other assets, net of allowance for credit losses of $1 million and $2 million at December 31, 2021 and 2020, respectively	Other assets, net of allowance for credit losses of $1 million and $2 million at December 31, 2021 and 2020, respectively
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Interest, taxes and other liabilities	Interest, taxes and other liabilities