Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 254,904	$ 238,167	$ 215,713
OTHER COMPREHENSIVE INCOME (LOSS)
Unrealized holding gains (losses) arising during the period on available-for-sale securities	107,382	76,109	(13,626)
Unrealized holding gain on the transfer of held-to-maturity securities to available-for-sale per ASU 2017-12	0	2,547	0
Less: Reclassification adjustment for realized gains included in net income	54,806	13,314	61
Other comprehensive income (loss), before tax effect	52,576	65,342	(13,687)
Less: Tax effect of other comprehensive income (loss)	13,741	17,077	(3,577)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	38,835	48,265	(10,110)
COMPREHENSIVE INCOME	$ 293,739	$ 286,432	$ 205,603