Income Taxes: (Schedule of Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
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| Reconciliation of Unrecognized Tax Benefits [Roll Forward] | |||
| Beginning balance | $ 55 | $ 72 | $ 89 |
| Additions based on tax positions related to the current year | 6 | 7 | 12 |
| Additions for tax positions of previous years | 1 | 1 | 2 |
| Reductions for tax positions of prior years | 0 | (23) | (18) |
| Reductions due to lapse of statute of limitations | (2) | (3) | (6) |
| Settlements | 0 | 0 | (4) |
| Other | (4) | 1 | (3) |
| Ending balance | $ 56 | $ 55 | $ 72 |
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- Definition Unrecognized Tax Benefits, Other No definition available.
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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