v3.26.1
Fair Value Measurements and Derivatives - Derivatives Measured at Fair Value and Disclosed by Balance Sheet Location (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value $ 64,281 $ 33,307
Derivative liabilities, fair value 334,007 370,135
Derivatives    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 66,092 33,423
Derivative liabilities, fair value 336,108 370,135
Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 62,201 33,423
Derivative liabilities, fair value 52,540 26,565
Not Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 3,891  
Derivative liabilities, fair value 283,568 343,570
Fuel contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccruedLiabilitiesAndOtherLiabilities    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   116
Derivative liabilities, fair value   16,302
Fuel contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 9,088  
Derivative liabilities, fair value 1,385  
Fuel contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 1,789  
Derivative liabilities, fair value 2,527 7,829
Fuel contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:PrepaidExpenseAndOtherAssetsCurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 43,032  
Derivative liabilities, fair value 716  
Fuel contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccruedLiabilitiesAndOtherLiabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value   1,024
Fuel contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 46  
Fuel contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 22  
Derivative liabilities, fair value   114
Fuel contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:PrepaidExpenseAndOtherAssetsCurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 3,531  
Foreign currency contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccruedLiabilitiesAndOtherLiabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 36,642 2,434
Foreign currency contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 11,270  
Foreign currency contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:PrepaidExpenseAndOtherAssetsCurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 8,292 33,307
Foreign currency contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccruedLiabilitiesAndOtherLiabilities    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 8,574 594
Foreign currency contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 292  
Foreign currency contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 312  
Debt conversion options | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: nclc:ExchangeableNotesCurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 1,416  
Debt conversion options | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: nclc:ExchangeableNotesNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value $ 273,266 $ 341,838