Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Leases
Operating cash flows from operating leases	$ 186,059	$ 237,881
Operating cash flows from finance leases	13,602	4,775
Financing cash flows from finance leases	35,234	20,469
Operating leases	$ 32,863	72,947
Finance leases		175,311
Right-of-use assets and liabilities recognized at January 1, 2019 upon adoption of ASC 842		$ 730,180