Leases - Cash Payments Included in Measurement of Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finance leases:
Operating cash flows included in operating activities	$ 57	$ 67
Financing cash flows included in payments under finance lease obligations	354	459
Operating leases:
Operating cash flows (fixed payments) included in other operating activities, net	1,009	1,246
Operating cash flows (liability reduction) included in other operating activities, net	$ 967	$ 970