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Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2023 | Mar. 31, 2022
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Investments | $ 6 |
Securities |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 2 | $ 5
Residential Loans |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Acquisitions | 53 | 2,120
Business purpose loans |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Fair value option elected aggregate carrying amount, asset | 442 | 920
HEIs |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Acquisitions |  | 40
MSRs |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Acquisitions |  | $ 6
Shared home appreciation options |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |
Acquisitions | $ 17 |

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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. + References No definition available. + Details
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- Definition Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258 + Details
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- Definition Sum of the carrying amounts as of the balance sheet date of all investments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(h)) -URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910 + Details
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