Related Party Transactions - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Related Party Transactions [Abstract]
Related party transactions	$ 0	$ 0

Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

No definition available.

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