Securitization Activities and Consolidation - Non-Consolidated VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Assets [Abstract]
Investments in securities, at fair value	$ 79,189		$ 75,711
Accrued interest receivable	6,841		6,848
Derivative Assets, net	2,815		844
Other Assets	31,561	$ 22,992	22,799
Liabilities [Abstract]
Derivative Liabilities, net	2,226		372
Other Liabilities	7,848	$ 8,046	8,042
Variable Interest Entity, Not Primary Beneficiary [Member]
Assets [Abstract]
Investments in securities, at fair value	35,660		37,918
Accrued interest receivable	208		212
Derivative Assets, net	8		14
Other Assets	4,465		3,951
Liabilities [Abstract]
Derivative Liabilities, net	109		108
Other Liabilities	3,752		3,761
Maximum Exposure to Loss	322,557		307,820
Total Assets of Non-Consolidated VIEs	$ 342,265		$ 335,562