Segments (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)
Financial performance of operating segments
Number of reportable segments | segment			2
Net revenues	$ 4,379	$ 4,103	$ 8,549	$ 8,100
Operating income (loss)	741	854	1,541	1,780
Operating segments | Marketplaces
Financial performance of operating segments
Net transaction revenues	1,684	1,722	3,356	3,449
Marketing services and other revenues	432	452	829	880
Net revenues	2,116	2,174	4,185	4,329
Operating income (loss)	758	788	1,569	1,644
Operating segments | Payments
Financial performance of operating segments
Net transaction revenues	2,006	1,741	3,946	3,441
Marketing services and other revenues	254	205	422	350
Net revenues	2,260	1,946	4,368	3,791
Operating income (loss)	590	478	1,123	953
Elimination of inter-segment net revenue and other
Financial performance of operating segments
Net revenues	3	(17)	(4)	(20)
Corporate and other
Financial performance of operating segments
Operating income (loss)	$ (607)	$ (412)	$ (1,151)	$ (817)