Variable Interest Entities - Nonconsolidated Variable Interest Entities (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets in VIE	$ 128,603	$ 128,069
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Assets	10,390	9,526
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Liabilities	877	619
Maximum Exposure to Loss in Nonconsolidated VIEs	21,001	20,786
Retained Interests, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	2,846	3,372
Purchased Interests, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	2,418	901
Commitments and Guarantees, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	2,329	2,697
Derivatives, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	8,689	9,010
Debt and equity, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	4,719	4,806
Mortgage-Backed [Member]
Variable Interest Entity [Line Items]
Assets in VIE	77,153	75,354
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Assets	3,323	3,830
Maximum Exposure to Loss in Nonconsolidated VIEs	3,766	3,946
Mortgage-Backed [Member] | Retained Interests, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	2,690	3,223
Mortgage-Backed [Member] | Purchased Interests, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	631	607
Mortgage-Backed [Member] | Commitments and Guarantees, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	43	50
Mortgage-Backed [Member] | Derivatives, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	402	66
Corporate debt and other asset-backed [Member]
Variable Interest Entity [Line Items]
Assets in VIE	17,141	16,248
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Assets	3,598	2,040
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Liabilities	874	612
Maximum Exposure to Loss in Nonconsolidated VIEs	12,688	11,821
Corporate debt and other asset-backed [Member] | Retained Interests, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	156	149
Corporate debt and other asset-backed [Member] | Purchased Interests, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	1,787	294
Corporate debt and other asset-backed [Member] | Commitments and Guarantees, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	1,294	1,374
Corporate debt and other asset-backed [Member] | Derivatives, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	8,201	8,849
Corporate debt and other asset-backed [Member] | Debt and equity, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	1,250	1,155
Real estate, credit- and power-related and other investing [Member]
Variable Interest Entity [Line Items]
Assets in VIE	19,442	19,602
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Assets	3,066	3,243
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Liabilities	3	7
Maximum Exposure to Loss in Nonconsolidated VIEs	4,093	4,543
Real estate, credit- and power-related and other investing [Member] | Commitments and Guarantees, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	944	1,213
Real estate, credit- and power-related and other investing [Member] | Derivatives, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	83	92
Real estate, credit- and power-related and other investing [Member] | Debt and equity, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	3,066	3,238
Investment In Funds [Member]
Variable Interest Entity [Line Items]
Assets in VIE	14,867	16,865
Carrying Value of the Firm's Variable Interests in Nonconsolidated VIEs - Assets	403	413
Maximum Exposure to Loss in Nonconsolidated VIEs	454	476
Investment In Funds [Member] | Commitments and Guarantees, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	48	60
Investment In Funds [Member] | Derivatives, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	3	3
Investment In Funds [Member] | Debt and equity, Maximum Exposure to Loss [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Nonconsolidated VIEs	$ 403	$ 413