Variable Interest Entities and Securitization Activities - Non-Consolidated VIEs (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entity
Carrying value of variable interests—Assets	$ 1,188,140	$ 1,115,862
Additional VIE assets owned	15,392	20,019
Carrying value of variable interests—Liabilities	1,081,542	1,012,713
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
VIE assets (UPB)	146,071	184,153
MABS
Variable Interest Entity
VIE assets (UPB)	146,071	184,153
Maximum exposure to loss	18,833	27,176
CDO
Variable Interest Entity
VIE assets (UPB)	667	3,527
Maximum exposure to loss	129	257
MTOB
Variable Interest Entity
VIE assets (UPB)	6,089	6,524
Maximum exposure to loss	4,100	4,425
Operating entities
Variable Interest Entity
VIE assets (UPB)	2,086	2,161
Maximum exposure to loss	1,459	1,187
Other
Variable Interest Entity
VIE assets (UPB)	52,111	48,241
Maximum exposure to loss	16,943	17,396
Assets | MABS | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	18,062	26,247
Assets | CDO | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	129	257
Assets | MTOB | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	5	5
Assets | Operating entities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	1,459	1,187
Assets | Other | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	12,345	11,859
Debt and equity interests | MABS
Variable Interest Entity
Maximum exposure to loss	18,062	26,247
Debt and equity interests | MABS | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	18,062	26,247
Debt and equity interests | CDO
Variable Interest Entity
Maximum exposure to loss	129	257
Debt and equity interests | CDO | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	129	257
Debt and equity interests | MTOB
Variable Interest Entity
Maximum exposure to loss	0	0
Debt and equity interests | MTOB | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	0	0
Debt and equity interests | Operating entities
Variable Interest Entity
Maximum exposure to loss	1,459	1,187
Debt and equity interests | Operating entities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	1,459	1,187
Debt and equity interests | Other
Variable Interest Entity
Maximum exposure to loss	10,339	11,008
Debt and equity interests | Other | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	10,339	11,008
Derivative and other contracts | MABS
Variable Interest Entity
Maximum exposure to loss	0	0
Derivative and other contracts | MABS | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	0	0
Derivative and other contracts | CDO
Variable Interest Entity
Maximum exposure to loss	0	0
Derivative and other contracts | CDO | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	0	0
Derivative and other contracts | MTOB
Variable Interest Entity
Maximum exposure to loss	4,100	4,425
Derivative and other contracts | MTOB | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	5	5
Derivative and other contracts | Operating entities
Variable Interest Entity
Maximum exposure to loss	0	0
Derivative and other contracts | Operating entities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	0	0
Derivative and other contracts | Other
Variable Interest Entity
Maximum exposure to loss	5,599	5,639
Derivative and other contracts | Other | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Assets	2,006	851
Commitments, guarantees and other | MABS
Variable Interest Entity
Maximum exposure to loss	771	929
Commitments, guarantees and other | CDO
Variable Interest Entity
Maximum exposure to loss	0	0
Commitments, guarantees and other | MTOB
Variable Interest Entity
Maximum exposure to loss	0	0
Commitments, guarantees and other | Operating entities
Variable Interest Entity
Maximum exposure to loss	0	0
Commitments, guarantees and other | Other
Variable Interest Entity
Maximum exposure to loss	1,005	749
Derivative and other contracts | MABS | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Liabilities	0	0
Derivative and other contracts | CDO | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Liabilities	0	0
Derivative and other contracts | MTOB | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Liabilities	0	0
Derivative and other contracts | Operating entities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Liabilities	0	0
Derivative and other contracts | Other | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Carrying value of variable interests—Liabilities	$ 362	$ 222