Leases - Maturity of Lease Liabilities and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Nov. 30, 2018
Maturity of Lease Liabilities
Nine months ending December 31, 2019	$ 2,201	$ 2,201
2020	7,242	7,242
2021	9,481	9,481
2022	9,746	9,746
2023	10,024	10,024
Thereafter	70,172	70,172
Total operating lease payments	108,866	108,866
Less: Estimated tenant improvement allowance	(15,721)	(15,721)
Less: Imputed interest	(37,692)	(37,692)
Present value of operating lease liabilities	55,453	55,453
Operating cash flows from operating leases	$ 2,100	$ 6,000
Weighted-average remaining lease term (years)	10 years 4 months 24 days	10 years 4 months 24 days
Weighted-average discount rate	8.65%	8.65%
9.0% non-recourse notes due 2033
Maturity of Lease Liabilities
Interest rate (as a percent)	9.00%	9.00%	9.00%