Summary of Significant Accounting Policies - Allowance for Merchant Credit Losses (Details) - Merchant credit losses - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Aggregate merchant credit losses incurred	$ 80	$ 62	$ 41
Collateral held	700	1,500
Loss contingency accrual	$ 36	$ 29