Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jan. 01, 2019
Lessee Lease Description [Line Items]
Right-of-use lease assets	$ 12,667	$ 12,667
Operating lease, initial lease liabilities	$ 12,973	$ 12,973
Operating lease, weighted-average remaining lease term	78 months	78 months
Operating lease, expense	$ 800	$ 1,700
Operating lease, payments	$ 1,100	$ 2,100
Accounting Standards Update 2016-02
Lessee Lease Description [Line Items]
Right-of-use lease assets			$ 13,700
Operating lease, initial lease liabilities			$ 14,500
San Diego, California
Lessee Lease Description [Line Items]
Operating leases, remaining lease term		78 months
Jersey City, New Jersey
Lessee Lease Description [Line Items]
Operating leases, remaining lease term		6 months