Related Party Transactions - Additional Information (Detail) (Detail) - Principal Owner $ in Thousands	3 Months Ended
Mar. 31, 2018 USD ($)
Related Party Transaction [Line Items]
Rent Expense	$ 201
Minimum
Related Party Transaction [Line Items]
Non controlling ownership interest minimum	10.00%

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

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