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Subsequent Events (Details) - Brex Inc. - Subsequent Event shares in Millions, $ in Millions	Jan. 22, 2026 USD ($) shares
Subsequent Event [Line Items]
Fair value of purchase consideration	$ 5,150
Total cash consideration for acquisition	$ 2,580
Number of shares of Capital One treasury stock issued in the acquisition (in shares) | shares	10.6

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Number of shares of equity interest issued or issuable by acquirer as part of consideration transferred in business combination.

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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