New Accounting Standards Cumulative Effect of Changes due to Adoption (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets, current	$ 3,169	$ 3,922	$ 3,930
Other assets, non-current	10,789	9,253	7,929
Deferred Tax Liabilities, Net		10,408
Other Liabilities and Deferred Revenue, Current		20,872
Other Liabilities and Deferred Revenue, Noncurrent		24,571
Retained Earnings (Accumulated Deficit)	$ 22,769	22,681	22,668
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets, current			3,930
Other assets, non-current			7,929
Deferred Tax Liabilities, Net			10,412
Other Liabilities and Deferred Revenue, Current			20,556
Other Liabilities and Deferred Revenue, Noncurrent			23,588
Retained Earnings (Accumulated Deficit)			$ 22,668
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets, current		(8)
Other assets, non-current		1,324
Deferred Tax Liabilities, Net		(4)
Other Liabilities and Deferred Revenue, Current		316
Other Liabilities and Deferred Revenue, Noncurrent		983
Retained Earnings (Accumulated Deficit)		$ 13