Derivatives and Hedging Activities - After Tax Impact of Foreign Currency Forward Contracts, Designated as Net Investment Hedging Instruments (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Other Comprehensive Income (Loss), Net of Tax [Member] \| Foreign Currency Contracts [Member] \| Derivative Instruments Designated as Net Investment Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion of Gain (Loss) Recognized on Foreign Currency Forward Contracts	$ 3,537	$ (4,981)

Amount, after tax, of reclassification from accumulated other comprehensive income (AOCI) of gain (loss) from increase (decrease) in fair value of net investment hedge.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CCC
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998896-113959

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration