Loans and Leases - Composition of Loan and Lease Portfolio (Parenthetical) (Details) - USD ($) $ in Millions		6 Months Ended		12 Months Ended
		Jun. 30, 2021		Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		$ 43,518		$ 42,822
Deferred loan origination fees		0		2
Other Assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable		211		219
Lease Financing, Unearned Income
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned income		103		116
Non-Covered Loans		1,846		1,735
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	[2]	3,776	[1]	3,417	[3]
Commercial and Industrial | Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		1,930		1,682
Commercial and Industrial | Specialty Finance Loans | Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		3,200		3,000
Commercial and Industrial | Other Commercial and Industrial Loans | Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		$ 555		$ 393

[1] Includes lease financing receivables, all of which were classified as Pass.

[2] Includes specialty finance loans and leases of $3.2 billion and $3.0 billion, respectively, at June 30, 2021 and December 31, 2020, and other C&I loans of $555 million and $393 million, respectively, at J

[3] Includes lease financing receivables, all of which were classified as Pass.