Commitments and Contingencies - Operating Lease Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Under Topic 840)
2019		$ 5,571
2020		5,684
2021		4,777
2022		1,659
2023		1,691
Thereafter		2,852
Total		$ 22,234
Operating Lease Liabilities, Payments Due (Under Topic 842)
2019 (excluding the nine months ended September 30, 2019)	$ 2,419
2020	4,819
2021	4,755
2022	4,577
2023	4,613
Thereafter	29,824
Total undiscounted lease payments	51,007
Present value adjustment	(13,401)
Net operating lease liabilities	$ 37,606