Lessee Leases - Minimum Future Payments on Non-Cancelable Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leased Assets [Line Items]
Remaining three months of 2019	$ 3,655
2020	13,576
2021	12,966
2022	11,832
2023	8,409
Thereafter	27,585
Total operating lease payments	78,023
Present value adjustment	(15,004)
Total operating lease liabilities	63,019
Operating lease liabilities, current portion	10,281	$ 10,300	$ 0
Long-term operating lease liabilities	$ 52,738	$ 59,791	$ 0
Minimum
Operating Leased Assets [Line Items]
Term of Contract (in years)	1 year
Maximum
Operating Leased Assets [Line Items]
Term of Contract (in years)	12 years