Note 9 - Marketable Securities - Amortized Cost and Unrealized Gain (Loss) (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Amortized cost (1)	[1]	$ 114,531	$ 12,064
Unrealized gains/(losses), net (1)	[1]	592,423	(2,711)
Marketable securities		$ 706,954	$ 9,353

[1] See Albertsons Companies, Inc. discussion below.