Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2019 (excluding the nine months ended September 30, 2019)	$ 19,016
2020	75,360
2021	59,295
2022	45,318
2023	37,300
Thereafter	55,740
Less: Imputed interest	(20,412)
Present value of lease liabilities	271,617
Current operating lease liabilities	$ 70,853	$ 0