Commitments and Contingencies - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Lease cost
Operating lease cost	$ 2,008	$ 2,044	$ 3,452	$ 4,053
Sublease income	0	(29)	0	(58)
Finance lease cost capitalized	589	0	589	0
Total lease cost	2,597	2,015	4,041	3,995
Operating cash flows from operating leases	1,285	1,779	2,508	3,546
Finance Lease, Liability, Payment, Due	0	0	1,208	0
Right-of-use assets obtained in exchange for new operating lease liabilities	4,996	3,691	5,074	5,387
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 18,858	$ 0	$ 18,858	$ 0
Weighted-average discount rate	7.30%	6.50%	7.30%	6.50%