ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Unrealized gains (loss) on available-for-sales securities:
Gain on sale of securities	$ 409	$ 1,239
Income tax expense	(7,719)	(12,576)	(2,857)
Net earnings	13,494	19,892	5,264
Unrealized gains (losses) on available-for-sale securities | Amount reclassified from accumulated other comprehensive income
Unrealized gains (loss) on available-for-sales securities:
Gain on sale of securities	409
Income tax expense	(172)
Net earnings	$ 237