Other Assets (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019		Mar. 31, 2018	Dec. 31, 2018
Mutual Fund Investments	[1]	$ 65			$ 79
Equity Securities, FV-NI	[1]	20			16
Federal Reserve Bank Stock	[1]	403			403
Federal Home Loan Bank Stock	[1]	366			227
Equity Securities without Readily Determinable Fair Value, Amount	[1]	68			68
Net Investment in Lease		4,084
Operating Lease, Right-of-Use Asset	[2]	1,164			0
Property Subject to or Available for Operating Lease, Net	[2]	1,146	[3],[4]		1,205
Build-to-Suit Lease Assets		774			735
Bank Owned Life Insurance		1,636			1,627
Accrued Investment Income Receivable		1,163			1,106
Receivables from Customers		854			602
Defined Benefit Plan, Funded (Unfunded) Status of Plan		479			484
Prepaid Expense		251			231
Other Real Estate	[5]	53			54
Other Assets, Miscellaneous		510			432
Other Assets		10,719			8,991
Equity Securities, FV-NI, Gain (Loss)	[6]	4		$ 1
Equity Securities without Readily Determinable Fair Value, Downward Price Adjustment, Annual Amount		0		0
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount	[6]	0		23
Equity Securities, FV-NI, Realized Gain (Loss)		0		0
Equity Securities [Member]
Unrealized Gain (Loss) on Securities		4		$ 24
Tax Credit Investments [Member]
Other Assets	[7]	$ 1,767			$ 1,722

[1] Does not include equity securities held for trading purposes classified as Trading assets and derivative instruments or Trading liabilities and derivative instruments on the Company’s Consolidated Balance Sheets. See Note 4, “Trading Assets and Liabilities and Derivative Instruments,” for more information.

[2] See Note 10, “Leases,” for additional information.

[3] Excludes owned assets subject to operating leases that are held and used by the Company and which are included in Premises, property, and equipment, net, on the Company's Consolidated Balance Sheets.

[4] Included in Other Assets on the Company's Consolidated Balance Sheets.

[5] Does not include foreclosed real estate related to loans insured by the FHA or guaranteed by the VA. Proceeds due from the FHA and the VA are recorded as a receivable in Other assets in the Consolidated Balance Sheets until the property is conveyed and the funds are received. The receivable related to proceeds due from the FHA and the VA totaled $50 million at both March 31, 2019 and December 31, 2018.

[6] Recognized in Other noninterest income in the Company's Consolidated Statements of Income.

[7] See Note 11, “Certain Transfers of Financial Assets and Variable Interest Entities,” for additional information