Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jul. 29, 2019
Business Acquisition [Line Items]
Restricted cash and cash equivalents	$ 42		$ 42
Interest expense	187	$ 47	309	$ 137
Interest income	23	$ 2	30	$ 3
First Data
Business Acquisition [Line Items]
Percentage of business acquired					100.00%
Merchant credit losses
Business Acquisition [Line Items]
Aggregate merchant credit losses incurred	17		17
Collateral held	510		510
Loss contingency accrual	$ 35		$ 35