Investment Securities (Details 2) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Amortized Cost
Due in one year or less	$ 3,240
Due after one year through five years	227,670
Due after five years through ten years	1,020,128
Due after ten years	2,432,483
Total securities available-for-sale	3,683,521	$ 4,017,909
Fair Value
Due in one year or less	3,248
Due after one year through five years	232,238
Due after five years through ten years	1,056,640
Due after ten years	2,525,222
Total securities available-for-sale	$ 3,817,348	$ 4,009,431