Note 2 - Significant Accounting Policies and Recent Accounting Pronouncements - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 276,002	$ 143,922	$ 148,928
Restricted cash - current portion	8,856	4,998	6,912
Restricted cash - non-current portion	68,670	42,976	40,031
Total cash, cash equivalents and restricted cash	$ 353,528	$ 191,896	$ 195,871

Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Balance Type:	debit
Period Type:	instant