Leases - Future Minimum Lease Payments (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Operating Lease Liabilities, Payments Due [Abstract]
2019 (excluding the three months ended March 31, 2019)	$ 58,082
2020	71,827
2021	55,609
2022	42,738
2023	35,777
Thereafter	52,794
Less: Imputed interest	(40,149)
Present value of lease liabilities	276,678
Current operating lease liabilities	$ 71,065