Investment Securities (Details 2) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Amortized Cost
Due in one year or less	$ 18,084
Due after one year through five years	235,439
Due after five years through ten years	879,297
Due after ten years	2,182,714
Total securities available-for-sale	3,315,534	$ 3,213,655
Fair Value
Due in one year or less	18,221
Due after one year through five years	238,871
Due after five years through ten years	885,026
Due after ten years	2,194,874
Total securities available-for-sale	$ 3,336,992	$ 3,223,830