LOAN SERVICING - Mortgage Servicing Rights Activity (Detail) - Mortgage Servicing Rights - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Servicing Assets at Fair Value [Line Items]
Mortgage loans sold with servicing retained	$ 5,729,000,000	$ 5,242,000,000
Mortgage loans sold with servicing retained	980,000,000	1,056,000,000	$ 1,762,000,000
Pre-tax net gains (losses) resulting from above loan sales	3,000,000	(12,000,000)	43,000,000
Mortgage servicing fees	14,000,000	13,000,000	12,000,000
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	52,800,000	44,400,000	35,600,000
Additions	11,300,000	13,000,000.0	19,200,000
Payoffs and curtailments	(2,200,000)	(4,400,000)	(12,800,000)
Impairment (charge) / recovery	(200,000)	2,500,000	4,800,000
Amortization	(2,200,000)	(2,700,000)	(2,400,000)
Balance at end of period	59,500,000	52,800,000	44,400,000
Fair value, beginning of period	68,600,000	46,000,000.0	35,600,000
Fair value, end of period	71,800,000	68,600,000	$ 46,000,000.0
Valuation allowance for servicing rights	$ 200,000	$ 0