Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Restricted cash and cash equivalents	$ 9,000,000		$ 9,000,000		$ 13,000,000
Allowance for doubtful accounts	50,000,000		50,000,000		48,000,000
Accumulated impairment loss	0		0
Equity securities without a readily determinable fair value	95,000,000		95,000,000		160,000,000
Ondot
Business Acquisition [Line Items]
Pre-tax gain from remeasurement			12,000,000
Merchant credit losses
Business Acquisition [Line Items]
Aggregate merchant credit loss expense	0	$ 35,000,000	31,000,000	$ 89,000,000
Collateral held	2,600,000,000		2,600,000,000		1,200,000,000
Merchant credit loss allowance	$ 45,000,000		$ 45,000,000		$ 59,000,000