Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Disaggregation of Revenue [Table Text Block]

	For the years ended December 31,
	2023			2022			2021
Guest ticket revenue:
Direct		53	%		50	%		56	%
National Geographic		12	%		14	%		14	%
Agencies		19	%		20	%		18	%
Affinity		6	%		5	%		5	%
Guest ticket revenue		90	%		89	%		93	%
Other tour revenue		10	%		11	%		7	%
Tour revenues		100	%		100	%		100	%

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

	Contract Liabilities
(In thousands)
Balance as of December 31, 2022	$	178,198
Recognized in tour revenues during the period		(548,052	)
Additional contract liabilities in period		463,760
Balance as of December 31, 2023	$	93,906

Schedule of Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Table Text Block]

	As of December 31,
	2023		2022		2021
(In thousands)
Cash and cash equivalents	$	156,845	$	87,177	$	150,753
Restricted cash		30,499		28,847		21,940
Total cash, cash equivalents and restricted cash as presented in the statement of cash flows	$	187,344	$	116,024	$	172,693

Restricted Cash and Marketable Securities [Table Text Block]

		As of December 31,
	2023		2022
(In thousands)
Credit card processor reserves	$	20,250	$	20,400
Federal Maritime Commission and other escrow		8,958		6,882
Certificates of deposit and other restricted securities		1,291		1,565
Total restricted cash	$	30,499	$	28,847

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]

	As of December 31,
	2023		2022
(In thousands)
Prepaid tour expenses	$	26,123	$	20,605
Marine operating supplies		5,438		9,961
Other		25,597		21,173
Total prepaid expenses and other current assets	$	57,158	$	53,704

Schedule Of Estimated Useful Lives [Table Text Block]

	Years
Vessels and vessel improvements	15	-	25
Furniture & equipment		5
Computer hardware and software	5	-	10
Leasehold improvements, including expedition sites and port facilities	Shorter of lease term or related asset life

Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]

	As of December 31,
	2023		2022
(In thousands)
Accrued other expense	$	48,901	$	54,418
Accounts payable		16,154		16,601
Total accounts payable and accrued expenses	$	65,055	$	71,019