Stock Repurchase Program, Additional Authorized Amount

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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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- Definition

Amount of stock repurchase plan authorized.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Stockholders' Equity (Deficit) - Repurchase of Common Stock (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 02, 2018	Jul. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program, additional authorized amount				$ 1,500,000,000
Number of common stock shares repurchased (in shares)	856,437
Treasury stock value	$ 34,600,000	$ 67,300,000	$ 571,700,000
Common stock repurchase (price per share)	$ 40.43
July 2015 Repurchase Program
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program, authorized amount				$ 1,000,000,000.0	$ 1,500,000,000
Common Stock Repurchase Set One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares repurchased (in shares)			14,898,454
Treasury stock value			$ 651,400,000
Common stock repurchase (price per share)			$ 43.72
Common Stock Repurchase Set Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares repurchased (in shares)			13,678,818
Treasury stock value			$ 571,400,000
Common stock repurchase (price per share)			$ 41.77
Common Stock Repurchase Set Three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares repurchased (in shares)		1,560,633
Treasury stock value		$ 67,200,000
Common stock repurchase (price per share)		$ 43.09