INVESTMENT SECURITIES (Details 6) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Scheduled maturities of investment securities available-for sale, amortized cost basis
Due within one year	$ 417,774,000
Due after one year through five years	547,189,000
Due after five years through ten years	750,811,000
Due after ten years	1,070,716,000
Total investment securities available-for-sale	2,786,490,000
Scheduled maturities of investment securities available-for sale, estimated fair value
Due within one year	401,970,000
Due after one year through five years	542,293,000
Due after five years through ten years	732,404,000
Due after ten years	1,057,130,000
Total investment securities available-for-sale	2,733,797,000
Par value of securities pledged to secure public deposits	$ 1,970,000,000	$ 1,780,000,000