Derivatives and Hedging Activities Derivatives and Hedging Activities (Schedule of Notional Amounts of Financial Instruments) (Parenthetical) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013 Designated as Hedging Instrument [Member]	Dec. 31, 2012 Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative notional amount		$ 150
Maturity period of cash flow hedges, maximum (in years)	three years