Discontinued Operations - Financial Results of Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating expenses:
Loss from discontinued operations, net of income taxes	$ (5)	$ (6)	$ (7)	$ (176)
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenues	0	676	0	5,598
Cost of net revenues	0	362	0	2,524
Gross profit	0	314	0	3,074
Operating expenses:
Sales and marketing	0	71	0	628
Product development	0	71	0	619
General and administrative	13	102	15	859
Provision for transaction and loan losses	0	34	0	427
Amortization of acquired intangible assets	0	3	0	100
Goodwill impairment	0	0	0	786
Total operating expenses	13	281	15	3,419
Loss from operations of discontinued operations	(13)	33	(15)	(345)
Interest and other, net	0	(2)	0	2
Loss from discontinued operations before income taxes	(13)	31	(15)	(343)
Income tax benefit/(expense)	8	(37)	8	167
Loss from discontinued operations, net of income taxes	$ (5)	$ (6)	$ (7)	$ (176)