Accounting Policies - Summary of Operating Lease Maturities (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Accounting Policies [Abstract]
2019	$ 1,864
2020	3,680
2021	3,491
2022	3,293
2023	3,099
Thereafter	4,706
Total lease payments	20,133
Less imputed interest	(2,347)
Total operating lease liabilities	$ 17,786