SEGMENT INFORMATION - Reconciliation of Reportable Segment Financial Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income (Loss):
Income before income taxes	$ 110,650	$ 27,302	$ 199,822	$ 26,601
Income tax	40,092	6,046	68,114	3,079
Net income	70,558	21,256	131,708	23,522
Segment Reconciling Items [Member]
Net Income (Loss):
Total income for segments and other	164,213	60,261	309,127	89,533
Other operating expenses	53,563	32,959	109,305	62,932
Income before income taxes	110,650	27,302	199,822	26,601
Income tax	40,092	6,046	68,114	3,079
Net income	70,558	21,256	131,708	23,522
Average assets:
Total average earning assets for segments	19,074,536	12,635,937	18,492,045	12,233,108
Average non-earning assets	1,109,941	950,071	1,146,337	936,610
Total consolidated average assets	$ 20,184,477	$ 13,586,008	$ 19,638,382	$ 13,169,718