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Fair Value Measurements - The carrying value and fair value of financial instruments (Details) - USD ($) $ in Millions | Mar. 31, 2026 | Dec. 31, 2025
--- | --- | ---
Financial assets: |  |
Mortgage loans | $ 961 | $ 947
Long-term debt | 1,820 | 1,820
Level 1 |  |
Financial assets: |  |
Cash and cash equivalents | 1,353 | 1,727
Mortgage loans | 0 | 0
Total financial assets not accounted for at fair value | 1,353 | 1,727
Long-term debt | 0 | 0
Total financial liabilities not accounted for at fair value | 0 | 0
Level 2 |  |
Financial assets: |  |
Cash and cash equivalents | 0 | 0
Mortgage loans | 0 | 0
Total financial assets not accounted for at fair value | 0 | 0
Long-term debt | 1,549 | 1,606
Total financial liabilities not accounted for at fair value | 1,549 | 1,606
Level 3 |  |
Financial assets: |  |
Cash and cash equivalents | 0 | 0
Mortgage loans | 953 | 937
Total financial assets not accounted for at fair value | 953 | 937
Long-term debt | 3 | 3
Total financial liabilities not accounted for at fair value | 3 | 3
Carrying Value |  |
Financial assets: |  |
Cash and cash equivalents | 1,353 | 1,727
Mortgage loans | 961 | 947
Total financial assets not accounted for at fair value | 2,314 | 2,674
Long-term debt | 1,820 | 1,820
Total financial liabilities not accounted for at fair value | 1,820 | 1,820
Fair Value |  |
Financial assets: |  |
Cash and cash equivalents | 1,353 | 1,727
Mortgage loans | 953 | 937
Total financial assets not accounted for at fair value | 2,306 | 2,664
Long-term debt | 1,552 | 1,609
Total financial liabilities not accounted for at fair value | $ 1,552 | $ 1,609

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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-10 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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