Leases - Maturities of Operating and Finance Lease Liabilities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Operating Leases
2019, excluding amounts already paid	$ 11,135
2020	13,667
2021	13,021
2022	12,309
2023	9,890
Thereafter	20,622
Total future lease payments	80,644
Less: amount representing interest	14,335
Total operating lease liabilities	66,309
Finance Leases
2019, excluding amounts already paid	5,240
2020	7,329
2021	7,476
2022	7,626
2023	7,780
Thereafter	10,521
Total future lease payments	45,972
Less: amount representing interest	6,888
Total finance lease liabilities	$ 39,084