Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases
Operating cash flows from operating leases	$ 61,808	$ 81,012
Operating cash flows from finance leases	4,798	1,195
Financing cash flows from finance leases	11,466	6,055
Operating leases	$ 6,749	47,321
Right-of-use assets and liabilities recognized at January 1, 2019 upon adoption of ASC 842		$ 730,180