Goodwill and Other Intangible Assets Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, beginning of period		$ 659,900
Goodwill, Impairment Loss	$ 270,300	270,300
Currency translation effect on foreign goodwill balances		3,300
Goodwill, end of period		392,900
Intangible Assets, Net (Excluding Goodwill)		694,400	$ 830,300
Intangible Assets, Net (Including Goodwill)		$ 1,087,300	$ 1,490,200

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

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