Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

Name:	us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Derivatives and Hedging Activity - Summary of Amounts of Derivative Gains (Losses) Recognized In Accumulated Other Comprehensive Loss (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), foreign currency transaction and translation adjustment, net of tax	$ 102.4	$ 249.9	$ (380.1)	$ (101.8)	$ (60.9)	$ 75.1
Foreign Exchange [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), foreign currency transaction and translation adjustment, net of tax	$ 0.4			$ 0.4			$ 0.8	$ 0.8