New Accounting Standards Adoption of New Accounting Standards (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets, Current	$ 3,339	$ 3,922	$ 3,930
Other Assets, Noncurrent	10,706	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)	$ 20,320	22,681	22,668
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets, Current			3,930
Other Assets, Noncurrent			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, Noncurrent		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