Leases - Operating Lease Commitments (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Operating Leases
2019	$ 49,757
2020	47,084
2021	44,480
2022	24,471
2023	20,309
Thereafter	75,190
Total future lease payments	261,291
Sublease Rental Income
2019	4,760
2020	3,944
2021	3,864
2022	707
2023	614
Thereafter	939
Total	$ 14,828