Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Gross amount of port costs included in passenger ticket revenues	$ 135,900	$ 158,700	$ 413,700	$ 443,100
Share-based compensation expense			(52,469)	(22,041)
Equity investment income	$ (85,120)	(46,539)	(120,359)	(94,832)
Amortization of debt issuance costs			$ (37,562)	(39,425)
Reclassification adjustment | Reclassification to Marketing, Selling and Administrative Expenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restructuring charges		$ 1,900		6,600
Reclassification adjustment | Share-based Compensation Expense (Cash Flows-Operating Activities)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Share-based compensation expense				(22,000)
Reclassification adjustment | Equity Investment Income (Cash Flows-Operating Activities)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity investment income				(94,800)
Reclassification adjustment | Amortization of Debt Issuance Costs (Cash Flows-Operating Activities)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of debt issuance costs				(22,900)
Reclassification adjustment | Other, net (Cash Flows-Operating Activities) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Share-based compensation expense				22,000
Equity investment income				94,800
Amortization of debt issuance costs				22,900
Reclassification adjustment | Reclassification From Decrease (Increase) In Prepaid Expenses And Other Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of debt issuance costs				11,300
Reclassification adjustment | Reclassification From Increase In Accrued Expenses and Other Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of debt issuance costs				5,300
Reclassification From Decrease (Increase) In Prepaid Expenses And Other Assets [Member] | Amortization of Debt Issuance Costs (Cash Flows-Operating Activities)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of debt issuance costs				(11,300)
Reclassification From Increase In Accrued Expenses and Other Liabilities [Member] | Amortization of Debt Issuance Costs (Cash Flows-Operating Activities)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of debt issuance costs				$ (5,300)