Business Combinations (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Business acquisition cost	$ 257
Acquisitions	209	$ 261
Other intangible assets	39
Mortgage servicing rights	15
Mortgage loans held for sale	5
Loans eligible for repurchase	70
Excess servicing spread financing	10
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Maximum value of contingent consideration	124
Innovative Residential Mortgage Subservicing Company
Business Acquisition [Line Items]
Maximum value of contingent consideration	124
Purchase price included in cash and consideration	145
Acquisitions	$ 131

Excess servicing spread financing.

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Loans eligible for repurchase.

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Amount of consideration transferred in asset acquisition. Includes, but is not limited to, cash, liability incurred by acquirer, and equity interest issued by acquirer.

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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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For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Fair value portion of mortgage loans held-for-sale.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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