Leases - Future Minimum Obligations under Topic 840 (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Capital Leases
2019	$ 294
2020	25
2021	0
2022	0
2023	0
Thereafter	0
Total future minimum payments	319
Leases, Operating [Abstract]
2019	110,794
2020	83,566
2021	72,606
2022	59,191
2023	56,123
Thereafter	133,716
Total future minimum payments	$ 515,996