Derivatives and Hedging Activities (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Derivatives and Hedging Activities (Textuals) [Abstract]
Net reduction in interest expense on long term debt and other	$ (38)	$ 14
Derivative asset not offset	0		$ 0
Derivative liabilities not offset	0		0
Margin On Interest Rate Swap Not Netted	70		84
Derivative [Line Items]
Cumulative amount of fair value hedging adjustment	(81)		(241)
Other Expense [Member]
Derivative [Line Items]
Gain (Loss) in Changes of Fair Value of Derivatives not designated as hedges	4	(21)
Gain on embedded derivatives	0	(2)
Fair Value Hedges [Member]
Derivative [Line Items]
Notional amount of long-term debt	22,800		24,000
Net Investment Hedges [Member]
Derivative [Line Items]
Effective portion of gain (loss) on hedges	(162)	(162)
Notional Amount of Foreign Currency Derivatives	9,500		9,600
Net Investment Hedges [Member] | Other Expense [Member]
Derivative [Line Items]
Amount reclassified from AOCI into income	0	$ 1
Carrying Value [Member]
Derivative [Line Items]
Notional amount of long-term debt	$ 22,600		$ 23,700