Leases - Maturities of Operating Lease Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Leases
2019 (three months remaining)	$ 1,360
2020	5,485
2021	5,323
2022	5,389
2023	5,510
Thereafter	12,336
Total lease payments	35,403
Less imputed interest	(9,952)
Total lease liabilities	25,451
Variable operating costs and real estate taxes	$ 3,000