Income Taxes (Net Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		$ 13,591	$ 13,128
Deferred tax liabilities		(14,502)	(15,150)
Valuation allowance		(95)	(105)
Deferred Tax Liabilities, Net	[1]	$ 1,006	$ 2,127

[1] Included in the net deferred tax (liabilities)/assets as of December 31, 2016 and 2015 are deferred tax assets in the amounts of $7,701 and $7,277 related to Accumulated other comprehensive loss.