Leases - Additional Information (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Lessee Lease Description [Line Items]
Operating lease description	The Company leases office space and equipment, and certain office space is subleased. Management determines if a contract is a lease at the inception of the arrangement and reviews all options to extend, terminate, or purchase its right-of-use assets at the inception of the lease and accounts for these options when they are reasonably certain of being exercised.
Right-of-use assets	$ 6,708
Lease liabilities	7,192
PA
Lessee Lease Description [Line Items]
Right-of-use assets	3,000
Lease liabilities	3,000
CA
Lessee Lease Description [Line Items]
Right-of-use assets	1,500
Lease liabilities	$ 1,500