AVAILABLE-FOR-SALE INVESTMENT SECURITIES (Details 5) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Scheduled maturities of available-for sale investment securities, Amortized Cost
Due within one year	$ 432,277
Due after one year through five years	1,407,326
Due after five years through ten years	328,129
Due after ten years	805,203
Total available-for-sale investment securities	2,972,935
Scheduled maturities of available-for sale investment securities, Estimated Fair Value
Due within one year	430,898
Due after one year through five years	1,414,615
Due after five years through ten years	325,541
Due after ten years	811,092
Fair Value	2,982,146	$ 2,626,365
Par value of securities pledged to secure public deposits	$ 1,680,000	$ 1,930,000