Leases - Maturities of Operating and Finance Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Operating Leases
2019, excluding amounts already paid	$ 3,740
2020	13,771
2021	13,996
2022	12,424
2023	10,012
Thereafter	20,549
Total future lease payments	74,492
Less: amount representing interest	12,952
Total operating lease liabilities	61,540
Finance Leases
2019, excluding amounts already paid	1,826
2020	7,447
2021	7,594
2022	7,744
2023	7,898
Thereafter	21,881
Total future lease payments	54,390
Less: amount representing interest	16,072
Total finance lease liabilities	$ 38,318