Note 4 - Financial Statement Details - Restricted Cash and Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Total restricted cash and marketable securities	$ 30,694	$ 30,499	$ 36,802
Credit Card Processor Reserves [Member]
Total restricted cash and marketable securities	12,750	20,250
Federal Maritime Commission Escrow [Member]
Total restricted cash and marketable securities	16,616	8,958
Certificates of Deposit and Other Restricted Securities [Member]
Total restricted cash and marketable securities	$ 1,328	$ 1,291