CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net earnings	$ 15,557	$ 5,264	$ 12,841	$ 20,821	$ 23,517
Other comprehensive income related to securities available-for-sale:
Unrealized holding gains arising during the period	8,185	7,409	9,974	15,594	11,154
Income tax expense related to urealized holding gains arising during the period	(3,439)	(3,111)	(4,189)	(6,550)	(4,685)
Reclassification adjustment for loss included in net earnings	1,115			1,115
Income tax benefit related to reclassification adjustment	(468)			(468)
Other comprehensive income	5,393	4,298	5,785	9,691	6,469
Comprehensive income	$ 20,950	$ 9,562	$ 18,626	$ 30,512	$ 29,986