Summary of Significant Accounting Policies (Details) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2015 USD ($) ship	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Significant Accounting Policies [Line Items]
Impact of voyage proration change, increase in Operating and Net Income	$ 36.8	$ 16.3	$ 53.2
Gross amount of port costs included in passenger ticket revenues			$ 561.1	$ 546.6	$ 494.2
Number of Cruise Ships | ship			44
Exchange gains (losses) recorded in other income (expense)			$ 34.6	49.5	13.4
Exposure under foreign currency forward contracts, foreign currency collar options, fuel call options, interest rate and fuel swap agreements	$ 4.8			4.8
Adjustments for New Accounting Pronouncement | Other Assets
Significant Accounting Policies [Line Items]
Reclassification to conform to current year presentation				41.9
Adjustments for New Accounting Pronouncement | Net deferred income tax (benefit) expense
Significant Accounting Policies [Line Items]
Reclassification to conform to current year presentation				3.4	3.3
Ships
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			30 years
Projected residual value			15.00%
Ships | Lower Limit
Significant Accounting Policies [Line Items]
Drydock services period			30 months
Ships | Upper Limit
Significant Accounting Policies [Line Items]
Drydock services period			60 months
Media advertising
Significant Accounting Policies [Line Items]
Advertising costs			$ 242.8	205.2	205.8
Brochure, production and direct mail costs
Significant Accounting Policies [Line Items]
Advertising costs			$ 127.1	$ 136.7	$ 137.1