Fair Value Measurements - Additional Information (Detail) $ in Millions	Sep. 30, 2019 USD ($)
Fair Value Disclosures [Abstract]
Fair value of other equity investments	$ 0.9

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

Name:	us-gaap_AvailableForSaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant