Commitments and Contingencies - Operating Lease Maturities (Details) - USD ($) $ in Thousands	Jun. 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 six months ended June 30, 2019)	$ 5,302
2020	4,549
2021	4,575
2022	4,577
2023	4,613
Thereafter	29,824
Total undiscounted lease payments	53,440
Present value adjustment	(13,861)
Net operating lease liabilities	$ 39,579

Amount of lessee's undiscounted obligation for lease payments for operating lease.

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