Consolidated Statements of Comprehensive Earnings - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
NET EARNINGS	$ 53,470	$ 42,093	$ 90,701	$ 80,345
OTHER ITEMS OF COMPREHENSIVE EARNINGS:
Change in unrealized gain on investment securities available-for-sale, before income taxes	36,524	37,057	109,561	72,071
Reclassification adjustment for realized gains on investment securities included in net earnings, before income taxes	(1,512)	(676)	(3,574)	(676)
Total other items of comprehensive earnings	35,012	36,381	105,987	71,395
Income tax expense related to other items of comprehensive earnings	(7,352)	(7,640)	(22,257)	(14,993)
COMPREHENSIVE EARNINGS	$ 81,130	$ 70,834	$ 174,431	$ 136,747