Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Disaggregation of Revenue [Table Text Block]

	For the years ended December 31,
	2021			2020			2019
Guest ticket revenue:
Direct		56	%		41	%		45	%
National Geographic		14	%		18	%		17	%
Agencies		18	%		25	%		23	%
Affinity		5	%		5	%		6	%
Guest ticket revenue		93	%		89	%		91	%
Other tour revenue		7	%		11	%		9	%
Tour revenues		100	%		100	%		100	%

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

	Contract Liabilities
(In thousands)
Balance as of January 1, 2021	$	73,267
Recognized in tour revenues during the period		(139,796	)
Additional contract liabilities in period		214,312
Balance as of December 31, 2021	$	147,783

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

	For the years ended December 31,
	2021		2020		2019
(In thousands)
Cash and cash equivalents	$	150,753	$	187,531	$	101,579
Restricted cash		21,940		16,984		7,679
Total cash, cash equivalents and restricted cash as presented in the statement of cash flows	$	172,693	$	204,515	$	109,258

Restricted Cash and Marketable Securities [Table Text Block]

	As of December 31,
	2021		2020
(In thousands)
Credit card processor reserves	$	10,536	$	1,945
Federal Maritime Commission escrow		9,814		13,856
Certificates of deposit and other restricted securities		1,590		1,183
Total restricted cash	$	21,940	$	16,984

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

	As of December 31,
	2021		2020
(In thousands)
Prepaid tour expenses	$	10,337	$	5,630
Prepaid marketing, commissions and other expenses		4,791		3,504
Prepaid client insurance		4,304		2,283
Prepaid air expense		4,051		3,817
Prepaid port agent fees		2,012		530
Prepaid corporate insurance		1,397		1,105
Prepaid income taxes		202		145
Total prepaid expenses	$	27,094	$	17,014

Schedule Of Estimated Useful Lives [Table Text Block]

	Years
Vessels and vessel improvements	15	-	25
Furniture & equipment		5
Computer hardware and software		5
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,
	2021		2020
(In thousands)
Accrued other expense	$	11,774	$	5,645
CERTS Grant		11,595		-
Accounts payable		9,692		5,285
Bonus compensation liability		5,348		2,963
Employee liability		4,396		3,495
Refunds and commissions payable		4,185		1,803
Royalty payable		887		-
Travel certificate liability		870		870
Accrued travel insurance expense		505		270
Income tax liabilities		-		2
Foreign currency forward contract liability		-		2,008
Total accounts payable and accrued expenses	$	49,252	$	22,341

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

	Loan Receivable
(In thousands)
Balance as of January 1, 2020	$	4,084
Accrued interest		161
Amortization of deferred costs		(25	)
Balance as of December 31, 2020		4,220
Adjustment for ship building expense		(390	)
Accrued interest		145
Amortization of deferred costs		(54	)
Legal invoices deferred		43
Balance as of December 31, 2021	$	3,964