Derivative Instruments and Hedging Activities (Outstanding Derivative Notionals and Terms by Type) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Derivative [Line Items]
Derivative, notional amount	$ 3,600
Libor and Euribor [Member] | Interest Rate Contract
Derivative [Line Items]
Derivative, notional amount	4,481
Argentina, Pesos | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, notional amount	187
Chilean Peso CLP [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, notional amount	410
Colombian Peso COP [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, notional amount	305
Other unspecified currency [Domain] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, notional amount	303
Unidad de Fomento (funds code) | Cross Currency Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, notional amount	$ 410