Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 81,826	$ 55,193	$ 185,445	$ 160,067
OTHER COMPREHENSIVE INCOME (LOSS)
Unrealized holding gains (losses) arising during the period on available-for-sale securities	18,736	(10,583)	79,547	(41,612)
Unrealized holding gain on the transfer of held-to-maturity securities to available-for-sale per ASU 2017-12	0	0	2,547	0
Less: Reclassification adjustment for realized gains (losses) included in net income	7,374	54	12,937	53
Other comprehensive gain (loss), before tax effect	11,362	(10,637)	69,157	(41,665)
Less: Tax effect of other comprehensive income (loss)	2,969	(2,780)	18,074	(10,889)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	8,393	(7,857)	51,083	(30,776)
COMPREHENSIVE INCOME	$ 90,219	$ 47,336	$ 236,528	$ 129,291