| 5.   Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) for the six months ended June 30, 2023 was as follows (in thousands):  
|  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Six Months Ended June 30, 2023 |  |  
|  |      |  |  |      |  |  |  | Change |  |  
|  |  | Accumulated |  | Change |  | Related to |  |  
|  |  | Other |  | Related to |  | Shipboard |  |  
|  |  | Comprehensive |  | Cash Flow |  | Retirement |  |  
|  |      | Income (Loss) |      | Hedges |  |  Plan |  |  
| Accumulated other comprehensive income (loss) at beginning of period |  | $ |  (477,079) |  | $ |  (480,578) |  | $ |  3,499 |    |  
| Current period other comprehensive loss before reclassifications |  |   |  (23,052) |  |   |  (23,052) |    |   |  — |    |  
| Amounts reclassified into earnings |  |   |  (7,199) |  |   |  (7,327) | (1) |   |  128 | (2) |  
| Accumulated other comprehensive income (loss) at end of period |  | $ |  (507,330) |  | $ |  (510,957) | (3) | $ |  3,627 |    |   Accumulated other comprehensive income (loss) for the six months ended June 30, 2022 was as follows (in thousands):  
|  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Six Months Ended June 30, 2022 |  |  
|  |      |  |  |      |  |  |  | Change |   |  
|  |  | Accumulated |  | Change |  | Related to |  |  
|  |  | Other |  | Related to |  | Shipboard |  |  
|  |  | Comprehensive |  | Cash Flow |  | Retirement |  |  
|  |      | Income (Loss) |      | Hedges |  |  Plan |  |  
| Accumulated other comprehensive income (loss) at beginning of period |   | $ |  (285,086) |  | $ |  (279,696) |  | $ |  (5,390) |   |  
| Current period other comprehensive income (loss) before reclassifications |   |   |  (48,818) |   |   |  (51,199) |    |   |  2,381 |   |  
| Amounts reclassified into earnings |   |   |  (43,388) |   |   |  (43,577) | (1) |   |  189 | (2) |  
| Accumulated other comprehensive income (loss) at end of period |   | $ |  (377,292) |   | $ |  (374,472) |  | $ |  (2,820) |   |  
| (1) | We refer you to Note 8 – “Fair Value Measurements and Derivatives” for the affected line items in the consolidated statements of operations. | 
 
| (2) | Amortization of prior-service cost and actuarial loss reclassified to other income (expense), net. | 
 
| (3) | Includes $24.0 million of loss expected to be reclassified into earnings in the next 12 months. | 
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