Consolidated Statements of Comprehensive Earnings (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract]
NET EARNINGS	$ 21,205	$ 19,490	$ 43,541	$ 38,067
OTHER ITEMS OF COMPREHENSIVE EARNINGS (LOSS):
Change in unrealized gain (loss) on investment securities available-for-sale, before income taxes	16,622	(35,988)	38,182	(42,103)
Reclassification adjustment for realized losses (gains) on investment securities included in net earnings, before income tax	1	(33)	5	(255)
Total other items of comprehensive earnings (losses)	16,623	(36,021)	38,187	(42,358)
Income tax benefit (expense) related to other items of comprehensive earnings	(5,818)	12,608	(13,365)	14,826
COMPREHENSIVE EARNINGS (LOSS)	$ 32,010	$ (3,923)	$ 68,363	$ 10,535