Employee Compensation and Benefit Plans - Schedule of Stock-based Compensation Expense and Related Income Tax Benefits (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 495	$ 424	$ 306
Income tax benefit related to stock-based compensation	$ 92	$ 81	$ 73
Restricted Stock Units and Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per stock award granted (in USD per share)	$ 73.25	$ 61.52	$ 60.21
Unrecognized compensation expense	$ 515	$ 547	$ 445
Weighted average period to be recognized (years)	1 year 7 months 6 days	1 year 9 months 18 days	1 year 10 months 24 days
Fair value of stock awards vested	$ 512	$ 471	$ 503

Unrecognized Compensation Expense

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Amount of noncash expense for share-based payment arrangement.

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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