STOCKHOLDERS' EQUITY (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Reclassifications out of accumulated other comprehensive income
Net gain on sales of investment securities	$ 5,577	$ 483
Total before tax	106,510	107,795
Tax expense	(34,419)	(39,712)
NET INCOME	72,091	68,083
Amount Reclassified from Accumulated Other Comprehensive Income
Reclassifications out of accumulated other comprehensive income
Total before tax	5,577
Tax expense	(2,342)
NET INCOME	3,235
Unrealized gain (loss) on investment securities available-for-sale | Amount Reclassified from Accumulated Other Comprehensive Income
Reclassifications out of accumulated other comprehensive income
Net gain on sales of investment securities	$ 5,577