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

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Amount, after tax, of expense for award under share-based payment arrangement.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Discount rate from fair value on purchase date that participants pay for shares.

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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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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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

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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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Number of shares issued under share-based payment arrangement.

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Number Of Offering Periods

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Equity-Based Compensation (Detail) $ in Millions	12 Months Ended
Equity-Based Compensation (Detail) $ in Millions	Dec. 31, 2019 USD ($) item shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	May 31, 2014 shares
2014 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available under employee stock plans	20,000,000.0
Maximum number of shares authorized for issuance				23,800,000
2009 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available under employee stock plans				1,100,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	30 days
Number of offering periods \| item	2
Price employees purchase shares (as a percent)	85.00%
Annual salary deducted for plan (as a percent)	10.00%
Shares issued under the plan	537,000	582,000	594,000
Shares available under employee stock plans	800,000
Compensation expense recognized \| $	$ 10	$ 9	$ 7
Compensation expense recognized, net of tax \| $	$ 7	$ 7	$ 4