Leases - Lease Portfolio (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2019
Jan. 01, 2019
Dec. 31, 2018
Lease Cost        
Operating lease cost $ 1,593 $ 2,633    
Short-term lease cost 20 96    
Variable lease cost 795 930    
Sublease income (299) (369)    
Total lease cost 2,109 3,290    
Operating Leases        
Operating lease, right-of-use-asset 27,643 27,643 $ 1,751  
Operating lease liabilities 5,076 5,076 616 $ 4,502
Operating lease liabilities, net of current portion $ 23,137 $ 23,137 $ 1,226 $ 41,441
Weighted average remaining lease term - operating leases 6 years 10 months 6 days 6 years 10 months 6 days    
Weighted-average discount rate - operating leases 7.92% 7.92%