Investments - Cost and Equity Method Investments (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Apr. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Cash investment		$ 7,603	$ 5,128
Long-term Investments
Schedule of Equity Method Investments [Line Items]
Cost and equity method investments		$ 130		$ 118
Flipkart | eBay.in Business
Schedule of Equity Method Investments [Line Items]
Cash investment	$ 500