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Investments in Unconsolidated Affiliates (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Mar. 31, 2024	Dec. 31, 2024
Investments in and Advances to Affiliates [Line Items]
Investments in unconsolidated affiliates		$ 1,538	$ 1,506			$ 1,506
Tax expense		190			$ 153
Equity securities without a readily determinable fair value		259	250			250
Equity securities without readily determinable fair value, upward price adjustment, annual amount		$ 0			$ 21
Wells Fargo Merchant Services (WFMS)
Investments in and Advances to Affiliates [Line Items]
Percentage of interest owned in affiliate		40.00%
Equity method investment, other-than-temporary impairment			25	$ 570		595
Tax expense						129
Wells Fargo Merchant Services (WFMS) \| Forecast
Investments in and Advances to Affiliates [Line Items]
Proceeds from divestiture of interest in joint venture	$ 453
Banc of America Merchant Services
Investments in and Advances to Affiliates [Line Items]
Investments in unconsolidated affiliates		$ 1,200	$ 1,200			$ 1,200