Expense Associated with Expense Acceleration in Connection with the Restructuring Plan

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Not Delivered Available for Reissue

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

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

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- Definition

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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- Definition

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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- Definition

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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- Definition

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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- Definition

Number of additional shares authorized for issuance under share-based payment arrangement.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Number of share options (or share units) exercised during the current period.

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Equity-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended			31 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	May 31, 2017
Deferred Stock Awards And Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation	$ 240,000,000	$ 235,000,000	$ 262,000,000
Accelerated recognition due to restructuring plan	29,000,000	4,000,000	45,000,000
Deferred Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Costs not yet recognized	199,000,000
Fair value for vested in period	$ 210,000,000	220,000,000	230,000,000
Period of recognition for unrecognized share-based compensation	2 years 3 months 18 days
Deferred Stock Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Deferred Stock Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Costs not yet recognized	$ 26,000,000
Fair value for vested in period	$ 30,000,000	$ 22,000,000	$ 32,000,000
Period of recognition for unrecognized share-based compensation	1 year 7 months 6 days
Performance Shares \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised (in shares)	0	0	0
Costs not yet recognized	$ 0
2017 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)					8,300,000
Additional shares authorized (in shares)				20,500,000
Shares awarded, but not delivered, available for reissue (in shares)	1,700,000
Shares available for grant (in shares)	19,200,000
2006 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)					28,500,000