Interest and Other, Net (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Nonoperating Income (Expense) [Abstract]
Interest income			$ 177	$ 125	$ 97
Interest expense			(292)	(225)	(144)
Gains on investments and sale of business			115	1,343	268
Other			11	83	(12)
Total interest and other, net			11	1,326	209
Gain (Loss) on Investments [Line Items]
Gain on sale of business			167	$ 0	$ 0
MercadoLibre, Inc.
Gain (Loss) on Investments [Line Items]
Pre-tax gain reclassified from OCI to income		$ 1,300
Proceeds from sale of investment		$ 1,300
Flipkart | eBay.in Business
Gain (Loss) on Investments [Line Items]
Gain on sale of business	$ 167		$ 167