Fair Value Measurements and Derivative Instruments - Nonrecurring (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, impairment		$ 576,208
Indefinite-life intangible asset, impairment		30,800
Right-of-use assets, impairment		45,900
Equity method investments, impairment		39,700
Total, impairment		1,108,118	$ 0
Silversea Cruises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, impairment		576,208
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-life intangible asset, impairment	[1]	30,800
Long-lived assets - vessels, impairment	[2]	417,057
Right-of-use assets, impairment	[3]	45,945
Equity method investments, impairment	[4]	39,735
Total, impairment		1,109,745
Nonrecurring | Silversea Cruises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, impairment	[5]	576,208
Nonrecurring | Total Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-life intangible asset		318,700
Long-lived assets - vessels	[2]	156,270
Right-of-use assets	[3]	57,068
Equity method investments	[4]	0
Total		1,040,617
Nonrecurring | Total Carrying Amount | Silversea Cruises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Silversea Cruises Goodwill	[5]	508,579
Nonrecurring | Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-life intangible asset		318,700
Long-lived assets - vessels	[2]	156,270
Right-of-use assets	[3]	57,068
Equity method investments	[4]	0
Total		1,040,617
Nonrecurring | Total Fair Value | Silversea Cruises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Silversea Cruises Goodwill	[5]	508,579
Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-life intangible asset	[1]	318,700
Long-lived assets - vessels	[2]	156,270
Right-of-use assets	[3]	57,068
Equity method investments	[4]	0
Total		$ 1,040,617
Nonrecurring | Level 3 | Discount rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets, measurement input		13.25%
Nonrecurring | Level 3 | Royalty fee percentage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets, measurement input		3.00%
Nonrecurring | Level 3 | Silversea Cruises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Silversea Cruises Goodwill	[5]	$ 508,579
Nonrecurring | Level 3 | Silversea Cruises | Weighted average cost of capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, measurement input		12.75%

[1] We estimated the fair value of our indefinite-life intangible asset using a discounted cash flow model and the relief-from-royalty method. The trade name relates to Silversea Cruises and we used a discount rate of 13.25%, comparable to the rate used in valuing the Silversea Cruises reporting unit. Significant inputs in performing the fair value assessment for the trade name were the royalty rate of 3.0% and forecasted net revenues, which takes into consideration expected ship deliveries, including ship options.

[2] We estimated the fair value of two of our vessels using a blended indication from the income and cost approaches. The fair value of the remaining vessels was estimated primarily based on their orderly liquidation values. A significant input in performing the fair value assessments for these vessels was management's expected use of the vessels, which takes into consideration forecasted operating results.

[3] Impairments to our right-of-use assets relate to certain of our berthing arrangements. We estimated the fair value of these right-of-use assets using estimated projected discounted cash flows. A significant input in performing the fair value assessments for these assets was our expected passenger headcount.

[4] We estimated the fair value of our other than temporarily impaired equity-method investments using a discounted cash flow model. A significant input in performing the fair value assessments for these assets was forecasted operating results for these investments.

[5] We estimated the fair value of the Silversea Cruises reporting unit using a probability-weighted discounted cash flow model in combination with a market based valuation approach. The principal assumptions used in the discounted cash flow model are projected operating results, weighted-average cost of capital and terminal value. Significantly impacting these assumptions were changes in market conditions associated with COVID-19 and its impact to the business and related operating plans. The discounted cash flow model used our 2020 projected operating results as a base. To that base we added future years’ cash flows through 2030 assuming multiple revenue and expense scenarios that reflect the impact of different global economic environments for this period on Silversea Cruises' reporting unit. We assigned a probability to each revenue and expense scenario. We discounted the projected cash flows using rates specific to Silversea Cruises' reporting unit based on its weighted-average cost of capital, which was determined to be 12.75%. A significant input in performing the fair value assessment for the Silversea Cruises goodwill was forecasted operating results, which takes into consideration expected ship deliveries, including ship options.