Note 6. Restricted marketable securities (Details) - Restricted marketable securities - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Restricted marketable securities	$ 217,172	$ 199,136
Product minimum service life	25 years
Restricted debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Restricted marketable securities	$ 217,172	199,136
Payments to acquire restricted marketable securities	5,000	7,900
Noncurrent restricted cash, held in trust [Member]
Debt Securities, Available-for-sale [Line Items]
Restricted cash and cash equivalents - noncurrent	6,900	5,000
U.S. debt [Member] \| Restricted debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Restricted marketable securities	115,350	109,155
Foreign government obligations [Member] \| Restricted debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Restricted marketable securities	54,156	49,024
Supranational debt [Member] \| Restricted debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Restricted marketable securities	28,276	22,809
U.S. government obligations [Member] \| Restricted debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Restricted marketable securities	$ 19,390	$ 18,148

Describes the solar modules minimum service life.

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Amount of restricted investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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The cash outflow to acquire investments (not to include restricted cash) that are pledged or subject to withdrawal restrictions.

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Amount of cash and cash equivalent restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate.

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