Leases- Schedule of Operating and Finance Lease Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
ROU assets:
Operating leases	$ 384	$ 64
Finance leases	$ 4	$ 4
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Premises and equipment	Premises and equipment
Total leased assets	$ 388	$ 68
Lease liabilities:
Operating leases	$ 385	$ 65
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities
Finance leases	$ 4	$ 4
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other borrowings	Other borrowings
Total lease liabilities	$ 389	$ 69
Weighted Average Remaining Lease Term [Abstract]
Weighted average remaining lease term, operating	9 years 10 months 24 days	8 years 10 months 24 days
Weighted average remaining lease term, finance	3 years 4 months 24 days	3 years 6 months
Weighted Average Discount Rate [Abstract]
Weighted average discount rate, operating lease	2.07%	3.00%
Weighted average discount rate, finance lease	3.11%	3.12%