Shareholders' Equity - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) shares in Thousands, $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted in period (in shares)	98,000
Year 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash-settled RSUs outstanding (in shares)	18,000
Key Employee Equity Plan, 3-year Vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting installments	3 years
Key Employee Equity Plan, 4-year Vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting installments	4 years
Key Employee Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation and benefits expense \| $	$ 269

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
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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The number of grants made 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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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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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An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

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-Publisher FASB
-Name Accounting Standards Codification
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