Commitments and Contingencies - Additional Information (Detail) $ in Thousands		3 Months Ended	12 Months Ended
	Jan. 05, 2018 USD ($) ft² building option	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($) Lease	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Leases [Abstract]
Rent expense under operating leases		$ 2,200	$ 10,200	$ 2,100
Sale Leaseback Transaction [Line Items]
Lessee, Sale Leaseback, Renewal Term	5 years
Sale Leaseback Transaction, Gross Proceeds, Investing Activities	$ 146,600		146,644
Number Of Buildings | building	4
Sale Leaseback Transaction, Number Of Buildings | building	2
Lessee, Operating Lease, Term of Contract	15 years
Area under new operating lease | ft²	125,000
Lessee, Sale Leaseback, Option To Extend, Number | option	2
Facility sold			15,000
Capital contributed			3,800
Cash transaction, netting			$ 7,000
Partnership that acquired the facility			25.00%
Lease payments			$ 900
Purchase commitment			9,100
Royalty And License Expense			$ 400	$ 600	$ 800
San Diego [Member]
Sale Leaseback Transaction [Line Items]
Number of extension | Lease			3
Lessee, Finance Lease, Term of Contract			10 years
Amended terms			P5Y