Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) segment	Sep. 30, 2020 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			1
Number of reportable segments | segment			1
Net revenues by type:
Total consolidated net revenue	$ 2,501	$ 2,258	$ 7,807	$ 6,416
U.S.
Net revenues by type:
Total consolidated net revenue	1,198	1,078	3,798	2,986
United Kingdom
Net revenues by type:
Total consolidated net revenue	450	425	1,451	1,196
Germany
Net revenues by type:
Total consolidated net revenue	272	265	953	795
Rest of world
Net revenues by type:
Total consolidated net revenue	581	490	1,605	1,439
Operating Segments
Net revenues by type:
Total consolidated net revenue	2,501	2,258	7,807	6,416
Operating Segments | Net transaction revenues
Net revenues by type:
Total consolidated net revenue	2,350	2,098	7,322	5,935
Operating Segments | Marketing services and other revenues
Net revenues by type:
Total consolidated net revenue	$ 151	$ 160	$ 485	$ 481