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Mortgage Servicing Rights - Summary of Adverse Changes to Weighted-Average Assumptions on the Fair Value of Servicing Rights (Details) - Mortgage servicing rights - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2023 | Dec. 31, 2022
Actual |  |
Option adjusted spread (percent) | 5.80% | 5.90%
Constant prepayment rate (as a percent) | 8.10% | 7.90%
Weighted average cost to service per loan | $ 68 | $ 68
10% adverse change |  |
Option adjusted spread (percent) | $ 1,014 | $ 1,012
Constant prepayment rate (as a percent) | 999 | 1,000
Weighted average cost to service per loan | 1,025 | 1,023
20% adverse change |  |
Option adjusted spread (percent) | 994 | 992
Constant prepayment rate (as a percent) | 966 | 970
Weighted average cost to service per loan | $ 1,015 | $ 1,013

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- Definition The hypothetical financial impact of a 10 percent adverse change of the specified assumption on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719 + Details
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- Definition The hypothetical financial impact of a 10 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719 + Details
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- Definition The hypothetical financial impact of a 20 percent adverse change of the specified assumption on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719 + Details
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- Definition A specified percentage variance in the prepayment speed assumption in the determination of fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719 + Details
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