Business Combinations - Net Assets Acquired (Details) - USD ($) $ in Millions		3 Months Ended
	Mar. 20, 2023	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Fair value adjustments:
Bargain purchase gain on Signature Transaction		$ 2,001	$ 159	$ 0
Signature Bridge Bank
Business Acquisition [Line Items]
Net assets acquired before fair value adjustments	$ 2,973
Fair value adjustments:
Loans	(727)
Core deposit and other intangibles	464
Certificates of deposit	27
Other net assets and liabilities	39
FDIC Equity Appreciation Instrument	(85)
Deferred tax liability	(690)
Bargain purchase gain on Signature Transaction	$ 2,001	$ 2,000