Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments in unconsolidated subsidiaries, fair value	$ 414	$ 378
Unamortized debt issuance costs	4,446	3,320
2.500% senior notes due in 2031 \| Carrying Value \| Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized debt issuance costs	177	196
Recurring \| Fair Value Measured at Net Asset Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments at fair value using NAV	22	21
Non-Marketable Equity Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Capital investments	$ 147	$ 148

Investments, Unconsolidated Subsidiaries, Fair Value

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The total fair value for all investments, comprising or included in the major category, of those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments) for which the entity has intentions to sell or liquidate, but the specific assets for sale or liquidation have not been identified (for example, the entity intends to sell $10,000,000 of its investments in private equity funds, but the individual investments to be sold have not been identified).

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