Leases - Supplemental cash flow and other information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating cash flows for operating leases	$ 12,048	$ 9,834
Operating cash flows for finance leases	1,914	1,704
Financing cash flows for finance leases	$ 2,579	$ 2,855	$ 7,626