Investment Securities, Available-for-sale Securities, Maturities (Details) $ in Thousands	Jun. 30, 2015 USD ($)
Amortized Cost [Abstract]
Due in one year or less	$ 2,546
Due in one year through five years	497,021
Due after five years through ten years	198,619
Due after ten years	18
Amortized Cost	698,204
Fair Value [Abstract]
Due in one year or less	2,542
Due in one year through five years	493,286
Due after five years through ten years	193,782
Due after ten years	18
Fair Value	$ 689,628