Income Taxes (Net Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		$ 10,722	$ 8,835
Deferred tax liabilities		(10,334)	(10,194)
Valuation allowance		(118)	(93)
Net deferred tax assets/(liabilities)	[1]	$ 270	$ (1,452)

[1] ⁽²⁾   Included in the net deferred tax assets/(liabilities) as of December 31, 2019 and 2018 are deferred tax assets in the amounts of $4,589 and $4,275 related to Accumulated other comprehensive loss.