Investments - Cost and Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Cash investment		$ 11,276	$ 7,782
Gain (Loss) on Disposition of Business		167	$ 0
Long-term Investments
Schedule of Equity Method Investments [Line Items]
Cost and equity method investments	$ 885	885		$ 118
Flipkart
Schedule of Equity Method Investments [Line Items]
Noncash or Part Noncash Acquisition, Interest Acquired	5.44%
Cash investment	$ 500
Cost Method Investments	725	$ 725
Flipkart | eBay.in Business
Schedule of Equity Method Investments [Line Items]
Gain (Loss) on Disposition of Business	$ 167