Quarterly Financial Data - Schedule of Quarterly Financial Information (Parenthetical) (Detail) $ in Millions	3 Months Ended
Dec. 31, 2018 USD ($)
Quarterly Financial Information Disclosure [Abstract]
Reclassification of non-controlling redeemable equity translation adjustments	$ 2.9

Adjustments to temporary equity resulting from foreign currency translation adjustments.

No definition available.

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