SEGMENT INFORMATION - Reconciliation of Reportable Segment Financial Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Income (Loss):
Income before income taxes	$ 190,638	$ 61,983	$ 130,259
Income tax (benefit) expense	(10,970)	(4,973)	37,030
Net income	201,608	66,956	93,229
Segment Reconciling Items [Member]
Net Income (Loss):
Segment income	298,185	167,407	231,385
Other operating expenses	(107,547)	(105,424)	(101,126)
Income before income taxes	190,638	61,983	130,259
Income tax (benefit) expense	(10,970)	(4,973)	37,030
Net income	201,608	66,956	93,229
Average assets:
Total average earning assets for segments	11,265,470	11,035,328	11,466,576
Average non-earning assets	940,731	937,950	923,566
Total consolidated average assets	$ 12,206,201	$ 11,973,278	$ 12,390,142