Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	*Basis of Presentation* The accompanying unaudited condensed consolidated financial statements and footnotes have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding unaudited interim financial information and include the accounts and transactions of the Company. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the Company’s financial statements for the periods presented. Operating results for the periods presented are not necessarily indicative of the results of operations to be expected for the full year due to seasonality and other factors. Certain information and footnote disclosures normally included in the consolidated financial statements in accordance with GAAP have been omitted in accordance with the rules and regulations of the SEC for interim reporting. All intercompany balances and transactions have been eliminated in these unaudited condensed consolidated financial statements. These unaudited condensed consolidated financial statements and footnotes should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto for the year ended December 31, 2021 contained in the Company’s Annual Report on Form 10-K filed with the SEC on February 28, 2022 (the “2021 Annual Report”). There have been no significant changes to the Company’s accounting policies from those disclosed in the 2021 Annual Report.
Return to Operations, Policy [Policy Text Block]	*Ramp of Fleet Operations and COVID-19 Business Update* The Company continued to ramp its operations during the second quarter of 2022, providing immersive expeditions across all ten of its owned vessels including trips to Alaska, the Arctic, the Galápagos Islands, Iceland, Norway and the Baltic and North Seas. Due to the spread of the COVID-19 virus and the effects of travel restrictions around the world, the Company suspended or rescheduled the majority of its expeditions departing between March 16, 2020 through May 31, 2021. Travel restrictions related to COVID-19 have diminished dramatically, and the Company continues to work with local authorities on plans to operate itineraries in additional geographies during the second half of 2022 and in 2023. Where travel restrictions remain, which also includes a limited number of itineraries impacted by the Russia-Ukraine conflict, the Company is adjusting itineraries where possible, and working with guests to reschedule travel plans and refund payments or issue future travel certificates, as applicable. The Company believes there are a variety of strategic advantages that enable it to deploy its ships safely and quickly, while mitigating the risk of COVID-19 as travel restrictions are lifted. The most notable is the size of its owned and operated vessels which range from 48 to 148 passengers, allowing for a highly controlled environment that includes stringent cleaning protocols. The small nature of the Company’s ships also allows it to efficiently and effectively test its guests and crew prior to boarding, or as otherwise needed. Additionally, all guests age five and older, crew and staff are required to be fully vaccinated and the majority of expeditions take place in remote locations where human interactions are limited, so there is less opportunity for external influence.
Balance Sheet and Liquidity, Policy [Policy Text Block]	*Balance Sheet and Liquidity* As of June 30, 2022, the Company had $126.9 million in unrestricted cash and $48.8 million in restricted cash primarily related to deposits on future travel originating from U.S. ports and credit card reserves. As of June 30, 2022, the Company had a total debt position of $578.2 million and was in compliance with all of its debt covenants in effect. The Company estimates that it will be in compliance with all applicable covenants over the next 12 months. During May 2022, the Company further amended its senior secured export credit agreements to extend the waiver of its net leverage coverage ratio from March 2022 through December 31, 2022. On February 4, 2022, the Company issued $360.0 million of 6.75% senior secured notes, maturing 2027, and entered into a new $45.0 million revolving credit facility, including a letter of credit sub-facility in an aggregate principal amount of up to $5.0 million. Proceeds from the senior secured note issuance were used primarily to pay the outstanding borrowings under the Company's prior credit agreement, including the term facility, Main Street Loan and the revolving credit facility. The senior secured notes are guaranteed on a senior secured basis by the Company and certain of the Company’s subsidiaries and are collateralized by certain of the Company’s assets.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2022

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements and footnotes have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding unaudited interim financial information and include the accounts and transactions of the Company. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the Company’s financial statements for the periods presented. Operating results for the periods presented are not necessarily indicative of the results of operations to be expected for the full year due to seasonality and other factors. Certain information and footnote disclosures normally included in the consolidated financial statements in accordance with GAAP have been omitted in accordance with the rules and regulations of the SEC for interim reporting. All intercompany balances and transactions have been eliminated in these unaudited condensed consolidated financial statements. These unaudited condensed consolidated financial statements and footnotes should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto for the year ended December 31, 2021 contained in the Company’s Annual Report on Form 10-K filed with the SEC on February 28, 2022 (the “2021 Annual Report”).

There have been no significant changes to the Company’s accounting policies from those disclosed in the 2021 Annual Report.

Return to Operations, Policy [Policy Text Block]

Ramp of Fleet Operations and COVID-19 Business Update

The Company continued to ramp its operations during the second quarter of 2022, providing immersive expeditions across all ten of its owned vessels including trips to Alaska, the Arctic, the Galápagos Islands, Iceland, Norway and the Baltic and North Seas. Due to the spread of the COVID-19 virus and the effects of travel restrictions around the world, the Company suspended or rescheduled the majority of its expeditions departing between March 16, 2020 through May 31, 2021. Travel restrictions related to COVID-19 have diminished dramatically, and the Company continues to work with local authorities on plans to operate itineraries in additional geographies during the second half of 2022 and in 2023. Where travel restrictions remain, which also includes a limited number of itineraries impacted by the Russia-Ukraine conflict, the Company is adjusting itineraries where possible, and working with guests to reschedule travel plans and refund payments or issue future travel certificates, as applicable.

The Company believes there are a variety of strategic advantages that enable it to deploy its ships safely and quickly, while mitigating the risk of COVID-19 as travel restrictions are lifted. The most notable is the size of its owned and operated vessels which range from 48 to 148 passengers, allowing for a highly controlled environment that includes stringent cleaning protocols. The small nature of the Company’s ships also allows it to efficiently and effectively test its guests and crew prior to boarding, or as otherwise needed. Additionally, all guests age five and older, crew and staff are required to be fully vaccinated and the majority of expeditions take place in remote locations where human interactions are limited, so there is less opportunity for external influence.

Balance Sheet and Liquidity, Policy [Policy Text Block]

Balance Sheet and Liquidity

As of June 30, 2022, the Company had $126.9 million in unrestricted cash and $48.8 million in restricted cash primarily related to deposits on future travel originating from U.S. ports and credit card reserves.

As of June 30, 2022, the Company had a total debt position of $578.2 million and was in compliance with all of its debt covenants in effect. The Company estimates that it will be in compliance with all applicable covenants over the next 12 months.

During May 2022, the Company further amended its senior secured export credit agreements to extend the waiver of its net leverage coverage ratio from March 2022 through December 31, 2022.

On February 4, 2022, the Company issued $360.0 million of 6.75% senior secured notes, maturing 2027, and entered into a new $45.0 million revolving credit facility, including a letter of credit sub-facility in an aggregate principal amount of up to $5.0 million. Proceeds from the senior secured note issuance were used primarily to pay the outstanding borrowings under the Company's prior credit agreement, including the term facility, Main Street Loan and the revolving credit facility. The senior secured notes are guaranteed on a senior secured basis by the Company and certain of the Company’s subsidiaries and are collateralized by certain of the Company’s assets.