Income Taxes (Net Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		$ 13,128	$ 14,219
Deferred tax liabilities		(15,150)	(16,028)
Valuation allowance		(105)	(81)
Net deferred tax (liabilities)/assets(2)	[1]	$ 2,127	$ 1,890

[1] Included in the net deferred tax (liabilities)/assets as of December 31, 2015 and 2014 are deferred tax assets in the amounts of $7,277 and $8,007 related to Accumulated other comprehensive loss.