LOAN SERVICING - Mortgage Servicing Rights Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Mortgage Servicing Rights
Servicing Assets at Fair Value [Line Items]
Mortgage loans sold with servicing retained	$ 5,242,000,000	$ 4,855,000,000
Mortgage loans sold with servicing retained	1,056,000,000	1,762,000,000	$ 1,636,000,000
Pre-tax net gains (losses) resulting from above loan sales	(12,000,000)	43,000,000	70,000,000
Mortgage servicing fees	13,000,000	12,000,000	12,000,000
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	44,400,000	35,600,000	42,600,000
Additions	13,000,000.0	19,200,000	16,000,000.0
Payoffs and curtailments	(4,400,000)	(12,800,000)	(14,800,000)
Impairment (charge) / recovery	2,500,000	4,800,000	(5,800,000)
Amortization	(2,700,000)	(2,400,000)	(2,400,000)
Balance at end of period	52,800,000	44,400,000	35,600,000
Fair value, beginning of period	46,000,000.0	35,600,000	45,200,000
Fair value, end of period	68,600,000	46,000,000.0	35,600,000
Valuation allowance for servicing rights	0	2,500,000
SBA-Guaranteed Loan Servicing
Servicing Assets at Fair Value [Line Items]
Mortgage loans sold with servicing retained	186,000,000	230,000,000
Mortgage loans sold with servicing retained	15,000,000	64,000,000	33,000,000
Pre-tax net gains (losses) resulting from above loan sales	1,000,000	8,000,000	3,000,000
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	3,000,000	3,000,000	3,000,000
Additions	0	1,000,000	1,000,000
Balance at end of period	2,000,000	3,000,000	3,000,000
Fair value, beginning of period	3,000,000	3,000,000	3,000,000
Fair value, end of period	2,000,000	3,000,000	$ 3,000,000
Valuation allowance for servicing rights	$ 1,600,000	$ 1,100,000