Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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-Publisher FASB
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-Section 50
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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.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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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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-Publisher FASB
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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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No definition available.

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Share-Based Compensation Plans - Restricted Share Units Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining amortization period (in years)	2 years 1 month 6 days
Restricted share units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of RSUs vested during the period	$ 190	$ 187	$ 189
Unamortized deferred compensation	$ 377
Restricted share units (RSUs) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted share units (RSUs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years