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Divestitures - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on divestitures and sale of investments	$ (9,000)		$ (9,000)	$ 18,435,000
Other Sales [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on divestitures and sale of investments	$ 0	$ 18,400,000	$ 0

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- Definition

The aggregate of gain (loss) from a divestiture or sale of a business activity, and the gain (loss) on the sale of an investment.

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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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No definition available.

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