Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Disaggregation of Revenue [Table Text Block]

	For the years ended December 31,
	2019			2018			2017
Guest ticket revenue:
Direct		45	%		45	%		45	%
National Geographic		17	%		19	%		19	%
Agencies		23	%		23	%		22	%
Affinity		6	%		4	%		4	%
Guest ticket revenue		91	%		91	%		90	%
Other tour revenue		9	%		9	%		10	%
Tour revenues		100	%		100	%		100	%

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

	Contract Liabilities
(In thousands)
Balance as of January 1, 2019	$	70,903
Recognized in tour revenues during the period		(263,767	)
Additional contract liabilities in period		264,915
Balance as of December 31, 2019	$	72,051

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

	For the years ended December 31,
	2019		2018		2017
(In thousands)
Cash and cash equivalents	$	101,579	$	113,396	$	96,443
Restricted cash		7,679		8,755		7,057
Total cash, cash equivalents and restricted cash as presented in the statement of cash flows	$	109,258	$	122,151	$	103,500

Restricted Cash and Marketable Securities [Table Text Block]

	As of December 31,
	2019		2018
(In thousands)
Federal Maritime Commission escrow	$	6,104	$	5,823
Certificates of deposit and other restricted securities		1,575		1,402
Credit card processor reserves		-		1,530
Total restricted cash	$	7,679	$	8,755

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

	As of December 31,
	2019		2018
(In thousands)
Prepaid tour expenses	$	15,630	$	10,617
Prepaid air expense		4,415		2,973
Prepaid marketing, commissions and other expenses		4,026		2,622
Prepaid client insurance		3,064		2,436
Prepaid corporate insurance		1,376		1,158
Prepaid port agent fees		491		1,433
Prepaid income taxes		53		24
Total prepaid expenses	$	29,055	$	21,263

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,
	2019		2018
(In thousands)
Accounts payable	$	14,633	$	9,326
Accrued other expense		8,348		11,464
Bonus compensation liability		5,322		5,195
Employee liability		3,712		2,943
Refunds and commissions payable		1,873		1,533
Foreign currency forward contract liability		1,300		387
Royalty payable		1,075		1,005
Travel certificate liability		888		1,088
Income tax liabilities		603		576
Accrued travel insurance expense		477		427
Total accounts payable and accrued expenses	$	38,231	$	33,944