LOAN PORTFOLIO- Selected Information on TDRs includes Recorded Investment by Loan Class and Modification Type (Detail) - Entity Loan Modification Program [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 582,647	$ 587,219	$ 647,048	$ 661,591
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	74,921	94,112
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	137,949	50,812
Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,935	2,184
Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	333,902	363,930
Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	10,382	11,783
Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	762	217
Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	35,100
Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	4,765	6,476
Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	18,031	22,605
Interest rate below market [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	28,771	35,947
Interest rate below market [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	664	2,510
Interest rate below market [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,966	6,563
Interest rate below market [Member] | Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Interest rate below market [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	22,729	25,964
Interest rate below market [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,396	892
Interest rate below market [Member] | Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Interest rate below market [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Interest rate below market [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	16	18
Interest rate below market [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Maturity or term extension [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	39,283	38,683
Maturity or term extension [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	19,769	20,648
Maturity or term extension [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,005	2,094
Maturity or term extension [Member] | Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	101	238
Maturity or term extension [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	11,586	8,318
Maturity or term extension [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,236	2,097
Maturity or term extension [Member] | Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	545	0
Maturity or term extension [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Maturity or term extension [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,524	3,941
Maturity or term extension [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,517	1,347
Combination of reduction in interest rateand extension of maturity [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	394,235	340,753
Combination of reduction in interest rateand extension of maturity [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	13,323	16,049
Combination of reduction in interest rateand extension of maturity [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	122,709	31,870
Combination of reduction in interest rateand extension of maturity [Member] | Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,186	1,946
Combination of reduction in interest rateand extension of maturity [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	239,348	267,578
Combination of reduction in interest rateand extension of maturity [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	5,651	6,891
Combination of reduction in interest rateand extension of maturity [Member] | Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Combination of reduction in interest rateand extension of maturity [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Combination of reduction in interest rateand extension of maturity [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,933	2,186
Combination of reduction in interest rateand extension of maturity [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	10,085	14,233
Forgiveness of principal and/or interest [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	275	35,317
Forgiveness of principal and/or interest [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forgiveness of principal and/or interest [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forgiveness of principal and/or interest [Member] | Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forgiveness of principal and/or interest [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forgiveness of principal and/or interest [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	275	217
Forgiveness of principal and/or interest [Member] | Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forgiveness of principal and/or interest [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	35,100
Forgiveness of principal and/or interest [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forgiveness of principal and/or interest [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,818	6,623
Forbearance Agreement [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,673	6,623
Forbearance Agreement [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member] | Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	145	0
Forbearance Agreement [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member] | Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Forbearance Agreement [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Other Loan Modifications [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	117,265	129,896
Other Loan Modifications [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	38,492	48,282
Other Loan Modifications [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,269	10,285
Other Loan Modifications [Member] | Finance Leases Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	648	0
Other Loan Modifications [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	60,094	62,070
Other Loan Modifications [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,824	1,686
Other Loan Modifications [Member] | Construction loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	217	217
Other Loan Modifications [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	0
Other Loan Modifications [Member] | Construction loans [Member] | Commercial Portfolio Segment [Member] | Land [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	292	331
Other Loan Modifications [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 6,429	$ 7,025