Leases - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2015	Dec. 31, 2019	Dec. 31, 2016	Dec. 31, 2018
Operating Leased Assets [Line Items]
Operating lease costs (gross lease expense)		$ 12,800
Variable lease costs		6,600
Sublease income		$ 7,500
Operating lease, Weighted average remaining operating lease term		8 years 5 months 4 days
Operating lease, weighted average discount rate, percent		7.40%
Financing obligation on leased facility		$ 0		$ 92,009
San Mateo Facility
Operating Leased Assets [Line Items]
Operating lease expiration period	Dec. 31, 2028
Capitalized construction costs			$ 71,800
Leasehold improvement costs reimbursed by landlord			$ 14,300
Financing obligation on leased facility				$ 92,000