SEGMENT INFORMATION - Reconciliation of Reportable Segment Financial Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Income (Loss):
Income before income taxes	$ 24,208	$ 65,595	$ 50,809	$ 185,825
Income tax (benefit) expense	4,405	(19,268)	1,326	(54,897)
Net income	28,613	46,327	52,135	130,928
Segment Reconciling Items [Member]
Net Income (Loss):
Total income for segments and other	69,436	95,781	158,969	271,005
Other operating expenses	(45,228)	(30,186)	(108,160)	(85,180)
Income before income taxes	24,208	65,595	50,809	185,825
Income tax (benefit) expense	(4,405)	19,268	(1,326)	54,897
Net income	28,613	46,327	52,135	130,928
Average assets:
Total average earning assets for segments	14,758,254	11,553,259	13,079,032	11,442,243
Average non-earning assets	1,047,401	933,250	975,744	964,799
Total consolidated average assets	$ 15,805,655	$ 12,486,509	$ 14,054,776	$ 12,407,042