v3.26.3
Fair Value Measurements and Derivatives - Derivatives Measured at Fair Value and Disclosed by Balance Sheet Location (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value $ 149,350 $ 33,307
Derivative liabilities, fair value 187,088 370,135
Derivatives    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 149,350 33,423
Derivative liabilities, fair value 187,088 370,135
Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 137,181 33,423
Derivative liabilities, fair value 73,496 26,565
Not Designated as Hedging Instrument    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value 12,169  
Derivative liabilities, fair value 113,592 343,570
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 25,848  
Fuel contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value   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 111,333  
Fuel contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: nclc:AccruedLiabilitiesAndOtherLiabilitiesCurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, fair value   116
Derivative liabilities, fair value   16,302
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 1,285  
Fuel 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   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 10,884  
Fuel contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: nclc:AccruedLiabilitiesAndOtherLiabilitiesCurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value   1,024
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   33,307
Foreign currency contracts | Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: nclc:AccruedLiabilitiesAndOtherLiabilitiesCurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 73,496 2,434
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 119  
Foreign currency contracts | Not Designated as Hedging Instrument | Location, Statement of Financial Position, Balance [Axis]: nclc:AccruedLiabilitiesAndOtherLiabilitiesCurrent    
Derivatives, Fair Value [Line Items]    
Derivative liabilities, fair value 7,986 594
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 $ 105,487 $ 341,838