ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 3,007,159	$ 2,757,596	$ 2,966,451	$ 2,647,088
Reclassification for gains included in net income, net of tax	0	0	0	0
Current year changes, net of tax	(10,794)	(1,066)	(28,225)	(8,481)
Balance at end of period	3,073,376	2,837,004	3,073,376	2,837,004
Unrealized Gain (Loss) on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(1,841)	26,090	15,590	33,505
Reclassification for gains included in net income, net of tax	0	0	0	0
Current year changes, net of tax	(10,794)	(1,066)	(28,225)	(8,481)
Balance at end of period	(12,635)	25,024	(12,635)	25,024
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(1,841)	26,090	15,590	33,505
Balance at end of period	$ (12,635)	$ 25,024	$ (12,635)	$ 25,024