Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended
Mar. 31, 2026	Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other equity investments	$ 475,000,000	$ 467,000,000
Impairment loss	0
Principal Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net asset value	8,000,000
Unfunded commitments	52,000,000
Carrying Amount \| Education Lending \| Discontinued operations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net of allowance	194,000,000	205,000,000
Estimate of Fair Value Measurement \| Education Lending \| Discontinued operations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net of allowance	146,000,000	155,000,000
Estimate of Fair Value Measurement \| Nonrecurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value on non recurring basis	$ 0	$ 0

Fair Value, Investments, Entities That Calculate Net Asset Value Per Share, Fair Value

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- Definition

Amount of investment in equity security without readily determinable fair value.

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- Definition

Amount of impairment loss on investment in equity security without readily determinable fair value.

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- Definition

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 amount of unfunded commitments for which the entity is obligated, to 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).

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- Definition

Fair value of financial and nonfinancial obligations.

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- Definition

Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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