Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($) $ in Millions		Mar. 31, 2020		Dec. 31, 2019		Mar. 31, 2019
Assets:
Cash and due from banks		$ 983		$ 1,744
Interest bearing deposits with banks		26,496		2,038
Securities purchased under agreements to resell		4,643		17,838
Trading assets		29,217		28,452
Loans		81,728		68,553
Other		8,272		6,723
Total assets		205,077	[1]	175,375	[1]	$ 180,921
Liabilities:
Deposits		136,723		119,693		$ 113,639
Trading liabilities		3,923		3,235
Short-term borrowings		17,579		3,659
Long-term debt		24,777		26,697
Other		3,756		3,835
Total liabilities	[1]	186,758		157,119
Affiliated Entity [Member]
Assets:
Cash and due from banks		199		850
Interest bearing deposits with banks		97		40
Securities purchased under agreements to resell	[2]	673		4,600
Trading assets		159		79
Loans		3,087		2,343
Other	[2]	728		456
Total assets		4,943		8,368
Liabilities:
Deposits		17,360		9,000
Trading liabilities		402		293
Short-term borrowings		5,418		1,166
Long-term debt		4,849		7,848
Other	[2]	212		931
Total liabilities		$ 28,241		$ 19,238

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2020 and December 31, 2019 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. Assets: Loans $39 million and $0 million. Other assets $92 million and $98 million. Total assets $131 million and $98 million respectively. Liabilities: Interest, taxes and other liabilities $32 million and $38 million. Total liabilities $32 million and $38 million, respectively.

[2] Other assets and other liabilities primarily consist of derivative balances associated with hedging activities and other miscellaneous account receivables and payables.