CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 25,077	$ 23,851	$ 74,324	$ 62,581
OTHER COMPREHENSIVE INCOME (LOSS), NET OF INCOME TAXES:
Unrealized holding gain (loss) on available-for-sale securities arising during the period	493	(4,659)	5,841	14,043
Income tax (expense) benefit related to available-for-sale securities unrealized holding gain (loss)	(202)	1,677	(2,116)	(5,060)
Reclassification for net gains on available-for-sale securities realized in earnings	(270)	(735)	(230)	(376)
Income tax expense related to available-for-sale securities realized gains	97	265	84	136
Other comprehensive income (loss)	118	(3,452)	3,579	8,743
COMPREHENSIVE INCOME	$ 25,195	$ 20,399	$ 77,903	$ 71,324