NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES
Net interest income	$ 41,104	$ 35,053	$ 83,041	$ 66,198
Provision for loan losses	2,700	2,250	5,100	4,250
Net interest income after provision for loan losses	$ 38,404	$ 32,803	$ 77,941	$ 61,948