Leases - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) a Mile
Lessee Lease Description [Line Items]
Number of area not to use within the radius of land lease | Mile	560
Estimated incremental borrowing rate	8.20%
Operating lease, lease payment, description	The minimum yearly rent is adjusted every three years to an amount equal to 80% of the average accounting year rent actually paid for the three previous years.
Number of percentage of average accounting year rent adjusted on minimum yearly rent	80.00%
Rent expense	$ 10.4
Operating lease payments related to options to extend lease terms	8.2
Operating Expenses and Selling, General and Administrative Expenses [Member]
Lessee Lease Description [Line Items]
Short term rent expense	0.8
ASU 2016-02 [Member]
Lessee Lease Description [Line Items]
Lease asset net balance reclassified	$ 14.0
City of San Deigo [Member]
Lessee Lease Description [Line Items]
Number of land lease area | a	190
Mission Bay Park, California (Premises) [Member]
Lessee Lease Description [Line Items]
Number of land lease area | a	17
Current lease term	2048-06
Rent expense	$ 1.7
Maximum [Member]
Lessee Lease Description [Line Items]
Term of lease	12 months
Lease renewal term	10 years
Minimum [Member]
Lessee Lease Description [Line Items]
Lease renewal term	1 year