Occupancy Expense and Information Systems and Communications Expense - Summary of Future Minimum Lease Payments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
2021	$ 186
2022	167
2023	147
2024	112
2025	93
Thereafter	275
Total future minimum lease payments	980
Less imputed interest	(89)
Total	891
Finance Leases
2021	41
2022	41
2023	31
2024	0
2025	0
Thereafter	0
Total future minimum lease payments	113
Less imputed interest	(10)
Total	103	$ 136
2021	227
2022	208
2023	178
2024	112
2025	93
Thereafter	275
Total future minimum lease payments	1,093
Less imputed interest	(99)
Total	$ 994

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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