Retirement Benefit Plans - Additional Information (Detail) - Foreign-based Defined Benefit Plans [Member] $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($)
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contribution towards defined benefit plans	$ 11.3
Expected contribution during remainder of year	$ 8.2

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration