Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Recent Accounting Pronouncements Revenue from Contracts with Customers In May 2014, amended GAAP guidance was issued to clarify the principles used to recognize revenue for all entities. The guidance also requires more detailed disclosures and provides additional guidance for transactions that were not comprehensively addressed in the prior accounting guidance. This guidance must be applied using one of two retrospective application methods and will be effective for our annual reporting period beginning after December 15, 2017, including interim periods therein. We have made significant progress toward completing our evaluation of potential changes to our core revenues using the five-step model supported by the new revenue standard. Based on our preliminary assessment, we do not expect the adoption of the new standard to materially change the timing of recognition of our core revenues, but we do anticipate enhancing our disclosures with respect to our revenue recognition policies in compliance with the new standard. We will continue to evaluate the impact of adopting this new standard on our consolidated financial statements, and expect to have our evaluation completed during the fourth quarter of fiscal 2017. Upon adoption, we intend to elect the modified retrospective method. This will involve applying the guidance retrospectively only to the most current period presented in the consolidated financial statements and recognizing the cumulative effect of initially applying the guidance as an adjustment to the January 1, 2018 opening balance of retained earnings. Leases In February 2016, amended GAAP guidance was issued to increase the transparency and comparability of lease accounting among organizations. For leases with a term greater than 12 months, the amendments require the lease rights and obligations arising from the leasing arrangements, including operating leases, to be recognized as assets and liabilities on the balance sheet. The amendments also expand the required disclosures surrounding leasing arrangements. The guidance must be applied using a retrospective application method and will be effective for financial statements issued for fiscal years beginning after December 15, 2018 and interim periods within those years. Early adoption is permitted. We are currently evaluating the impact of the adoption of this newly issued guidance to our consolidated financial statements. Classification of Certain Cash Receipts and Cash Payments In August 2016, amended GAAP guidance was issued to clarify how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments are aimed at reducing the existing diversity in practice. The guidance should be applied using a retrospective transition method to each period presented and will be effective for annual periods beginning after December 15, 2017 and interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. We intend to adopt the guidance on the date of initial application, January 1, 2018. The adoption of this newly issued guidance is not expected to have a material impact to our consolidated financial statements. Intra-Entity Transfers of Assets Other Than Inventory In October 2016, amended GAAP guidance was issued that requires the income tax consequences of an intra-entity transfer of an asset, other than inventory, to be recognized at the time that the transfer occurs, rather than when the asset is sold to an outside party. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2017. Early adoption is permitted as of the beginning of an annual period for which financial statements have not been issued. The guidance is required to be adopted retrospectively by recording a cumulative-effect adjustment to retained earnings as of the beginning of the adoption period. The adoption of this newly issued guidance is not expected to have a material impact to our consolidated financial statements. Service Concession Arrangements In May 2017, amended GAAP guidance was issued to reduce the diversity in practice in accounting for service concession arrangements. The amendments in this updated guidance provide clarity in determining the customer in a service concession arrangement and enables more consistent application of other aspects of the revenue guidance, which are affected by this customer determination. This guidance must be applied using one of two retrospective application methods and will be effective for our annual reporting period beginning after December 15, 2017, including interim periods therein. We are currently evaluating the impact of the adoption of this newly issued guidance to our consolidated financial statements. Other Revenues and expenses include port costs that vary with guest head counts. The amounts of such port costs included in Passenger ticket revenues on a gross basis were $143.4 million and $140.0 million for the second quarters of 2017 and 2016, respectively, and $277.9 million and $284.4 million for the six months ended June 30, 2017 and 2016, respectively. Reclassifications For the second quarter and six months ended June 30, 2016, restructuring charges of $4.4 million and $4.7 million, respectively, have been reclassified into Marketing, selling and administrative expenses in the consolidated statements of comprehensive income (loss) in order to conform to the current year presentation. For the six months ended June 30, 2016, share-based compensation expense of $13.3 million, equity investment income of $48.3 million and amortization of debt issuance costs of $14.7 million, have been reclassified in the consolidated statements of cash flows from Other, net to Share-based compensation expense, Equity investment income and Amortization of debt issuance costs, respectively, within Net cash provided by operating activities in order to conform to the current year presentation. Additionally, for the six months ended June 30, 2016, amortization of debt issuance costs of $7.7 million and $3.5 million, have been reclassified from Increase in prepaid expenses and other assets and from Decrease (increase) in accrued expenses and other liabilities, respectively, in the consolidated statements of cash flows to Amortization of debt issuance costs, within Net cash provided by operating activities in order to conform to the current year presentation.

Summary of Significant Accounting Policies

Recent Accounting Pronouncements

Revenue from Contracts with Customers

In May 2014, amended GAAP guidance was issued to clarify the principles used to recognize revenue for all entities. The guidance also requires more detailed disclosures and provides additional guidance for transactions that were not comprehensively addressed in the prior accounting guidance. This guidance must be applied using one of two retrospective application methods and will be effective for our annual reporting period beginning after December 15, 2017, including interim periods therein.

We have made significant progress toward completing our evaluation of potential changes to our core revenues using the five-step model supported by the new revenue standard. Based on our preliminary assessment, we do not expect the adoption of the new standard to materially change the timing of recognition of our core revenues, but we do anticipate enhancing our disclosures with respect to our revenue recognition policies in compliance with the new standard. We will continue to evaluate the impact of adopting this new standard on our consolidated financial statements, and expect to have our evaluation completed during the fourth quarter of fiscal 2017.

Upon adoption, we intend to elect the modified retrospective method. This will involve applying the guidance retrospectively only to the most current period presented in the consolidated financial statements and recognizing the cumulative effect of initially applying the guidance as an adjustment to the January 1, 2018 opening balance of retained earnings.

Leases

In February 2016, amended GAAP guidance was issued to increase the transparency and comparability of lease accounting among organizations. For leases with a term greater than 12 months, the amendments require the lease rights and obligations arising from the leasing arrangements, including operating leases, to be recognized as assets and liabilities on the balance sheet. The amendments also expand the required disclosures surrounding leasing arrangements. The guidance must be applied using a retrospective application method and will be effective for financial statements issued for fiscal years beginning after December 15, 2018 and interim periods within those years. Early adoption is permitted. We are currently evaluating the impact of the adoption of this newly issued guidance to our consolidated financial statements.

Classification of Certain Cash Receipts and Cash Payments

In August 2016, amended GAAP guidance was issued to clarify how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments are aimed at reducing the existing diversity in practice. The guidance should be applied using a retrospective transition method to each period presented and will be effective for annual periods beginning after December 15, 2017 and interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. We intend to adopt the guidance on the date of initial application, January 1, 2018. The adoption of this newly issued guidance is not expected to have a material impact to our consolidated financial statements.

Intra-Entity Transfers of Assets Other Than Inventory

In October 2016, amended GAAP guidance was issued that requires the income tax consequences of an intra-entity transfer of an asset, other than inventory, to be recognized at the time that the transfer occurs, rather than when the asset is sold to an outside party. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2017. Early adoption is permitted as of the beginning of an annual period for which financial statements have not been issued. The guidance is required to be adopted retrospectively by recording a cumulative-effect adjustment to retained earnings as of the beginning of the adoption period. The adoption of this newly issued guidance is not expected to have a material impact to our consolidated financial statements.

Service Concession Arrangements

In May 2017, amended GAAP guidance was issued to reduce the diversity in practice in accounting for service concession arrangements. The amendments in this updated guidance provide clarity in determining the customer in a service concession arrangement and enables more consistent application of other aspects of the revenue guidance, which are affected by this customer determination. This guidance must be applied using one of two retrospective application methods and will be effective for our annual reporting period beginning after December 15, 2017, including interim periods therein. We are currently evaluating the impact of the adoption of this newly issued guidance to our consolidated financial statements.

Other

Revenues and expenses include port costs that vary with guest head counts. The amounts of such port costs included in Passenger ticket revenues on a gross basis were $143.4 million and $140.0 million for the second quarters of 2017 and 2016, respectively, and $277.9 million and $284.4 million for the six months ended June 30, 2017 and 2016, respectively.

Reclassifications

For the second quarter and six months ended June 30, 2016, restructuring charges of $4.4 million and $4.7 million, respectively, have been reclassified into Marketing, selling and administrative expenses in the consolidated statements of comprehensive income (loss) in order to conform to the current year presentation.

For the six months ended June 30, 2016, share-based compensation expense of $13.3 million, equity investment income of $48.3 million and amortization of debt issuance costs of $14.7 million, have been reclassified in the consolidated statements of cash flows from Other, net to Share-based compensation expense, Equity investment income and Amortization of debt issuance costs, respectively, within Net cash provided by operating activities in order to conform to the current year presentation.

Additionally, for the six months ended June 30, 2016, amortization of debt issuance costs of $7.7 million and $3.5 million, have been reclassified from Increase in prepaid expenses and other assets and from Decrease (increase) in accrued expenses and other liabilities, respectively, in the consolidated statements of cash flows to Amortization of debt issuance costs, within Net cash provided by operating activities in order to conform to the current year presentation.