| Assets and Liabilities Measured at Fair Value on a Recurring Basis | Assets and liabilities measured at fair value on a recurring basis as of September 30, 2023 are as follows:  
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (in thousands) |  | Level 1 |  | Level 2 |  | Level 3 |  | Total |  
| Assets: |  |  |  |  |  |  |  |  |  
| Cash equivalents: |  |  |  |  |  |  |  |  |  
| Money market funds |  | $ | 60,120 |  |  | $ | — |  |  | $ | — |  |  | $ | 60,120 |  |  
|  |  |  |  |  |  |  |  |  |  
| 
Time deposits (1)
 |  | — |  |  | 19,412 |  |  | — |  |  | 19,412 |  |  
| Short-term investments: |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
| Money market funds |  | 302 |  |  | — |  |  | — |  |  | 302 |  |  
| Mutual fund shares |  | 1,172 |  |  | — |  |  | — |  |  | 1,172 |  |  
| Prepaid expenses and other current assets: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | — |  |  | 21,606 |  |  | — |  |  | 21,606 |  |  
| Other non-current assets: |  |  |  |  |  |  |  |  |  
| Money market funds |  | 1,699 |  |  | — |  |  | — |  |  | 1,699 |  |  
| Mutual fund shares |  | 21,879 |  |  | — |  |  | — |  |  | 21,879 |  |  
| Derivative financial instruments |  | — |  |  | 6,511 |  |  | — |  |  | 6,511 |  |  
| Total assets measured at fair value |  | $ | 85,172 |  |  | $ | 47,529 |  |  | $ | — |  |  | $ | 132,701 |  |  
| Liabilities: |  |  |  |  |  |  |  |  |  
| Accrued liabilities: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | $ | — |  |  | $ | 2,361 |  |  | $ | — |  |  | $ | 2,361 |  |  
| Other long-term liabilities: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | — |  |  | 104 |  |  | — |  |  | 104 |  |  
| Total liabilities measured at fair value |  | $ | — |  |  | $ | 2,465 |  |  | $ | — |  |  | $ | 2,465 |  | 
(1) Time deposits are carried at amortized cost on the unaudited Condensed Consolidated Balance Sheet, which reasonably approximates fair value.
 Assets and liabilities measured at fair value on a recurring basis as of September 30, 2022 are as follows:  
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (in thousands) |  | Level 1 |  | Level 2 |  | Level 3 |  | Total |  
| Assets: |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
| Short-term investments: |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
| Money market funds |  | $ | 79 |  |  | $ | — |  |  | $ | — |  |  | $ | 79 |  |  
| Mutual fund shares |  | 893 |  |  | — |  |  | — |  |  | 893 |  |  
| Prepaid expenses and other current assets: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | — |  |  | 35,201 |  |  | — |  |  | 35,201 |  |  
| Other non-current assets: |  |  |  |  |  |  |  |  |  
| Money market funds |  | 1,201 |  |  | — |  |  | — |  |  | 1,201 |  |  
| Mutual fund shares |  | 17,332 |  |  | — |  |  | — |  |  | 17,332 |  |  
| Derivative financial instruments |  | — |  |  | 13,919 |  |  | — |  |  | 13,919 |  |  
| Total assets measured at fair value |  | $ | 19,505 |  |  | $ | 49,120 |  |  | $ | — |  |  | $ | 68,625 |  |  
| Liabilities: |  |  |  |  |  |  |  |  |  
| Accrued liabilities: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | $ | — |  |  | $ | 1,514 |  |  | $ | — |  |  | $ | 1,514 |  |  
| Other long-term liabilities: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | — |  |  | 436 |  |  | — |  |  | 436 |  |  
| Total liabilities measured at fair value |  | $ | — |  |  | $ | 1,950 |  |  | $ | — |  |  | $ | 1,950 |  |  | Assets and liabilities measured at fair value on a recurring basis as of December 31, 2022 are as follows:  
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (in thousands) |  | Level 1 |  | Level 2 |  | Level 3 |  | Total |  
| Assets: |  |  |  |  |  |  |  |  |  
| Cash equivalents: |  |  |  |  |  |  |  |  |  
| Money market funds |  | $ | 120,481 |  |  | $ | — |  |  | $ | — |  |  | $ | 120,481 |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
| Short-term investments: |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  
| Money market funds |  | 80 |  |  | — |  |  | — |  |  | 80 |  |  
| Mutual fund shares |  | 642 |  |  | — |  |  | — |  |  | 642 |  |  
| Prepaid expenses and other current assets: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | — |  |  | 23,333 |  |  | — |  |  | 23,333 |  |  
| Other non-current assets: |  |  |  |  |  |  |  |  |  
| Money market funds |  | 1,456 |  |  | — |  |  | — |  |  | 1,456 |  |  
| Mutual fund shares |  | 19,026 |  |  | — |  |  | — |  |  | 19,026 |  |  
| Derivative financial instruments |  | — |  |  | 7,153 |  |  | — |  |  | 7,153 |  |  
| Total assets measured at fair value |  | $ | 141,685 |  |  | $ | 30,486 |  |  | $ | — |  |  | $ | 172,171 |  |  
| Liabilities: |  |  |  |  |  |  |  |  |  
| Accrued liabilities: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | $ | — |  |  | $ | 3,782 |  |  | $ | — |  |  | $ | 3,782 |  |  
| Other long-term liabilities: |  |  |  |  |  |  |  |  |  
| Derivative financial instruments |  | — |  |  | 1,770 |  |  | — |  |  | 1,770 |  |  
| Total liabilities measured at fair value |  | $ | — |  |  | $ | 5,552 |  |  | $ | — |  |  | $ | 5,552 |  |  |