Derivatives and Hedging Activities - Other derivatives not accounted for as hedges (Details 3) (Derivatives not accounted for hedges, Other fee revenue, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivatives not accounted for hedges | Other fee revenue
Derivative Instruments, Gain (Loss) [Line Items]
Location of Gain (Loss) Recognized in Income on Derivative	Other fee revenue	Other fee revenue	Other fee revenue	Other fee revenue
Amount of Gain (Loss) Recognized in Income on Customer Derivatives	$ 488	$ (1)	$ 740	$ 68