INVESTMENT SECURITIES (Details 2) (Available-for-sale Securities, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Available-for-sale Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings
Beginning balance	$ 124,340	$ 107,671
Addition of other-than-temporary impairment that was not previously recognized		6,340
Additional increases to the amount related to the credit loss for which an other-than-temporary impairment was previously recognized	633	10,329
Reduction for securities sold	(9,561)
Ending balance	$ 115,412	$ 124,340