Stock-Based Compensation - Summary of Stock Options Outstanding (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Stock Options, Stock options outstanding, Beginning Balance	3,572
Number of Stock Options, Stock options expired	(352)
Number of Stock Options, Stock options outstanding, Ending Balance	3,220	3,572
Number of Stock Options, Stock options exercisable	3,217
Weighted Avg. Exercise Price, Stock options outstanding, Beginning Balance	$ 22.88
Weighted Avg. Exercise Price, Stock options expired	21.48
Weighted Avg. Exercise Price, Stock options outstanding, Ending Balance	22.94	$ 22.88
Weighted Avg. Exercise Price, Stock options exercisable	$ 22.95
Weighted Avg. Remaining Contractual Life In Years, Stock options outstanding	2 years 8 months 12 days	3 years 4 months 24 days
Weighted Avg. Remaining Contractual Life in Years, Stock options exercisable	2 years 8 months 12 days
Aggregate Intrinsic Value, Stock options outstanding	$ 0

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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-Publisher FASB
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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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