Derivatives and Hedging Activities (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivatives And Hedging Activities Textuals [Abstract]
Net reduction in interest expense on long term debt	$ 22	$ 34
Derivative [Line Items]
Ineffectiveness reclassified from AOCI into income	0	0
Margin on interest rate swap not netted	155		$ 144
Derivative Instruments, Gain (Loss) [Line Items]
Net hedge ineffectiveness	0	0
Fair Value Hedging [Member]
Derivative [Line Items]
Notional amount of long-term debt	17,100		14,800
Net Investment Hedging [Member]
Derivative [Line Items]
Effection portion of loss on hedges	128	51
Credit Valuation Adjustment [Member]
Derivative [Line Items]
Notional amount of long-term debt	0	0
Other expense [Member]
Derivative [Line Items]
Gain (Loss) in Changes of Fair Value of Derivatives not designated as hedges	4	$ (1)
None Sold or Repledged [Member]
Offsetting Assets [Line Items]
Securities received as collateral	0		0
Risk Exposure Low [Member]
Offsetting Assets [Line Items]
Total derivatives assets,net	0		0
Individually Significant Counterparties [Member]
Offsetting Assets [Line Items]
Total derivatives assets,net	$ 0		$ 0