| 6.   Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) for the nine months ended September 30, 2020 was as follows (in thousands):  
|  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Nine Months Ended September 30, 2020 |  |  
|  |      |  |  |      |  |  |  | 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 |  | $ |  (295,490) |  | $ |  (289,362) |  | $ |  (6,128) |    |  
| Current period other comprehensive loss before reclassifications |  |   |  (163,672) |  |   |  (163,672) |    |   |  — |    |  
| Amounts reclassified into earnings |  |   |  87,158 |  |   |  86,853 | (1) |   |  305 | (2) |  
| Accumulated other comprehensive income (loss) at end of period |  | $ |  (372,004) |  | $ |  (366,181) | (3) | $ |  (5,823) |    |   Accumulated other comprehensive income (loss) for the nine months ended September 30, 2019 was as follows (in thousands):  
|  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Nine Months Ended September 30, 2019 |  |  
|  |      |  |  |      |  |  |  | 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 |   | $ |  (161,647) |  | $ |  (157,449) |  | $ |  (4,198) |   |  
| Current period other comprehensive loss before reclassifications |   |   |  (211,548) |   |   |  (211,548) |    |   |  — |   |  
| Amounts reclassified into earnings |   |   |  (16,438) |   |   |  (16,722) | (1) |   |  284 | (2) |  
| Accumulated other comprehensive income (loss) at end of period |   | $ |  (389,633) |   | $ |  (385,719) |  | $ |  (3,914) |   |  
| (1) | We refer you to Note 9 – “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, net. | 
 
| (3) | Includes $75.0 million of loss expected to be reclassified into earnings in the next 12 months. | 
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