Derivatives and Hedging Activities Interest Rate Swap Gains or Losses (Details) (Interest Rate Swap, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest Expense
Pre-Tax Gains or Losses
Amount of loss reclassified from OCI to interest expense	$ (993)	$ 0	$ 0
Other Non-Interest Expense
Pre-Tax Gains or Losses
Amount of loss recognized in other non-interest expense (ineffective portion)	0	0	0
Other Comprehensive Income
Pre-Tax Gains or Losses
Amount of (loss) gain recognized in OCI (effective portion)	$ (19,557)	$ 18,728	$ (7,926)