Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Operating Leases
2019 (April 1 - December 31)	$ 17,904
2020	22,265
2021	19,545
2022	17,251
2023	15,071
2024	12,754
2025 and thereafter	23,372
Total lease payments	128,162
Less: Imputed interest	28,796
Lease liabilities	99,366
Finance Leases
2019 (April 1 - December 31)	286
2020	294
2021	200
2022	94
2023	73
2024	3
2025 and thereafter	0
Total lease payments	950
Less: Imputed interest	175
Lease liabilities	$ 775