Derivative Instruments - (Details 1) (Not designated as hedging instruments:, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	$ 2,687	$ 1,534
Included in interest income on loans | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	557	779
Included in gains on sales of mortgage loans held for sale | Interest rate lock commitments
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	2,705	566
Included in gains on sales of mortgage loans held for sale | Forward commitments
Derivatives, Fair Value [Line Items]
Gains (losses) on derivative financial instruments	$ (575)	$ 189