Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jul. 31, 2016
Income Taxes
Operating loss carryforwards		$ 7.5
Deferred income tax expense (benefit)				$ (12.0)
Pullmantur | Trademarks and trade names
Income Taxes
Deferred tax liabilities	$ 43.4
Valuation allowance adjustment, deferred tax expense (benefit)	$ 31.4
Valuation allowance required as per projections (as a percent)	100.00%
Deferred income tax expense (benefit)	$ (12.0)
Other income (expense)
Income Taxes
Income tax expense (benefit)		18.3	$ 20.1	$ 11.1
Tax years between 2018 and 2024
Income Taxes
Operating loss carryforwards		$ 5.0
Pullmantur and CDF Croisieres De France
Income Taxes
Percentage of subsidiary which has been sold		51.00%			51.00%