Legal Matters - Additional Information (Details) $ in Millions		3 Months Ended		79 Months Ended
	Dec. 27, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 31, 2020 merchant
Loss Contingencies [Line Items]
Provision for legal matters		$ 1	$ 90
Return of takedown payment to the litigation escrow account	$ 467	467	0
Interchange Multidistrict Litigation
Loss Contingencies [Line Items]
Provision for legal matters		467	$ 0
Subsequent Event | U.K. Merchant Litigation
Loss Contingencies [Line Items]
Number of plaintiffs | merchant				500
Number of claims settled | merchant				100
Merchants with outstanding claims | merchant				400
Subsequent Event | U.K. Merchant Litigation | Threatened Litigation
Loss Contingencies [Line Items]
Number of plaintiffs | merchant				30
Visa, MasterCard, and Certain U.S. Financial Institutions
Loss Contingencies [Line Items]
Maximum takedown payments the defendants are entitled to		700
U.S. Covered Litigation [Member]
Loss Contingencies [Line Items]
Maximum takedown payments the defendants are entitled to		467
U.S. Covered Litigation [Member] | Interchange Multidistrict Litigation
Loss Contingencies [Line Items]
Provision for legal matters		$ 600
Return of takedown payment to the litigation escrow account	$ 467