Leases - Schedule of Operating Leases Included on Consolidated Statement of Financial Condition (Detail) $ in Millions |
Dec. 31, 2019
USD ($)
|
|---|---|
| Leases [Abstract] | |
| Operating lease ROU assets | $ 669 |
| Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | us-gaap:OtherAssets |
| Operating lease liability | $ 776 |
| Operating Lease, Liability, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilities |