Leases (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($) ft²	Jun. 30, 2019 USD ($) ft² location
Lessee, Lease, Description [Line Items]
Operating lease liabilities, current portion included in other accrued liabilities | $	$ 5,339	$ 5,339
Operating lease liabilities, long-term portion | $	29,275	29,275
Operating lease liabilities | $	$ 34,614	$ 34,614
Weighted average remaining lease term	3 years 3 months 29 days	3 years 3 months 29 days
Weighted average discount rate (as a percent)	10.77%	10.77%
Lease expense | $	$ 2,000	$ 3,800
Operating lease payments | $	$ 2,100
Corporate Headquarters Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	113,000	113,000
Number of office space locations | location		2
Term of lease	84 months	84 months
Renewal term of lease	5 years	5 years
"First Space" Sublease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	88,000	88,000
"Second Space" Sublease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	25,000	25,000
Corporate Headquarters Sublease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	25,879	25,879
Term of lease	48 months	48 months
Sublease receivable | $	$ 1,900	$ 1,900
Tukwila, WA lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	10,000	10,000
Term of lease	62 months	62 months
Renewal term of lease	5 years	5 years
Austin TX, Long-term Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	94,000	94,000
Term of lease	132 months	132 months