XML 38 R27.htm IDEA: XBRL DOCUMENT
v3.25.1

3. Restricted Marketable Securities (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2025
Debt Securities, Available-for-Sale, Restricted [Abstract] |
Schedule of restricted marketable securities | Restricted marketable securities consisted of the following as of March 31, 2025 and December 31, 2024 (in thousands):
|  | March 31, 2025 |  | December 31, 2024
U.S. debt |  | $ | 113,048 |  |  | $ | 109,155 |
Foreign government obligations |  | 50,592 |  |  | 49,024 |
Supranational debt |  | 28,118 |  |  | 22,809 |
U.S. government obligations |  | 18,797 |  |  | 18,148 |
Total restricted marketable securities |  | $ | 210,555 |  |  | $ | 199,136 |
Schedule of restricted marketable securities, including unrealized gain or loss | The following tables summarize the unrealized gains and losses related to our restricted marketable securities, by major security type, as of March 31, 2025 and December 31, 2024 (in thousands):
|  | As of March 31, 2025
|  | Amortized Cost |  | Unrealized Gains |  | Unrealized Losses |  | Fair Value
U.S. debt |  | $ | 144,193 |  |  | $ | — |  |  | $ | 31,145 |  |  | $ | 113,048 |
Foreign government obligations |  | 63,972 |  |  | — |  |  | 13,380 |  |  | 50,592 |
Supranational debt |  | 30,287 |  |  | 14 |  |  | 2,183 |  |  | 28,118 |
U.S. government obligations |  | 24,344 |  |  | — |  |  | 5,547 |  |  | 18,797 |
Total |  | $ | 262,796 |  |  | $ | 14 |  |  | $ | 52,255 |  |  | $ | 210,555 |
|  | As of December 31, 2024
|  | Amortized Cost |  | Unrealized Gains |  | Unrealized Losses |  | Fair Value
U.S. debt |  | $ | 144,652 |  |  | $ | — |  |  | $ | 35,497 |  |  | $ | 109,155 |
Foreign government obligations |  | 62,595 |  |  | — |  |  | 13,571 |  |  | 49,024 |
Supranational debt |  | 25,351 |  |  | — |  |  | 2,542 |  |  | 22,809 |
U.S. government obligations |  | 24,368 |  |  | — |  |  | 6,220 |  |  | 18,148 |
Total |  | $ | 256,966 |  |  | $ | — |  |  | $ | 57,830 |  |  | $ | 199,136 |

X
- Definition Schedule of Restricted Available For Sale Securities Reconciliation [Table Text Block] + References No definition available. + Details
Name: | fslr_ScheduleOfRestrictedAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | fslr_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Restricted Marketable Securities [Table Text Block] + References No definition available. + Details
Name: | fslr_ScheduleOfRestrictedMarketableSecuritiesTableTextBlock
Namespace Prefix: | fslr_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRestrictedAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration