Derivatives and Hedging Activities (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013
Exchange Cleared [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 2,000,000
Over the Counter [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 32,000,000