Investment Securities (Details 3) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Amortized Cost
Due in one year or less	$ 8,352
Due after one year through five years	252,427
Due after five years through ten years	714,467
Due after ten years	2,244,354
Total securities available-for-sale	3,219,600	$ 3,512,385
Fair Value
Due in one year or less	8,562
Due after one year through five years	259,096
Due after five years through ten years	738,034
Due after ten years	2,335,643
Total securities available-for-sale	$ 3,341,335	$ 3,559,437