INVESTMENT SECURITIES (Details 6) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Scheduled maturities of investment securities available-for sale, amortized cost basis
Due within one year	$ 238,822
Due after one year through five years	435,042
Due after five years through ten years	541,958
Due after ten years	1,024,674
Total investment securities available-for-sale	2,240,496
Scheduled maturities of investment securities available-for sale, fair value
Due within one year	234,661
Due after one year through five years	435,116
Due after five years through ten years	523,140
Due after ten years	1,044,931
Total investment securities available-for-sale	$ 2,237,848