Significant accounting policies.

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Amount of increase (decrease) in accumulated other comprehensive income (AOCI) for reclassification to retained earnings of tax effect from remeasurement of deferred tax pursuant to Tax Cuts and Jobs Act.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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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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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Amount of lessee's right to use underlying asset under operating lease.

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Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($) Segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments \| Segment	1
Impairments of goodwill		$ 234,200,000
Net transaction gains (losses)	$ (22,100,000)	(27,000,000)	$ (4,300,000)
ASU 2018-02
Significant Accounting Policies [Line Items]
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained earnings, Tax effect	10,000,000
ASU 2016-02
Significant Accounting Policies [Line Items]
Operating Lease asset	165,000,000
Operating lease liability	180,000,000
Continuing Operations
Significant Accounting Policies [Line Items]
Impairments of goodwill	$ 0	$ 0	$ 0
Minimum
Significant Accounting Policies [Line Items]
Other intangible assets, useful lives	3 years
Maximum
Significant Accounting Policies [Line Items]
Other intangible assets, useful lives	25 years