LOAN PORTFOLIO - Consumer Credit Exposure - Credit RiskProfile Based on Payment Activity (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	$ 8,858,123	$ 8,850,476	$ 8,886,873
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	3,163,208	3,290,957	3,296,031
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	1,944,713	1,749,897	1,716,628
Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	333,536	257,462
Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	3,016,003	3,152,018
Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	664,701	648,104
Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	946,476	844,331
Government-guaranteed mortgage loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	147,205	138,939
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	146,640	158,174	165,818
Financial Asset Acquired with Credit Deterioration [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	143,176	153,991	162,676
Financial Asset Acquired with Credit Deterioration [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	0	0	0
Financial Asset Acquired with Credit Deterioration [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	0	0
Financial Asset Acquired with Credit Deterioration [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	143,176	153,991
Financial Asset Acquired with Credit Deterioration [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	0	0
Financial Asset Acquired with Credit Deterioration [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	0	0
Financial Asset Acquired with Credit Deterioration [Member] | Government-guaranteed mortgage loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	0	0
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	7,951,214	7,901,994	7,833,150
Performing Financing Receivable [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	2,616,300	2,703,532	2,691,088
Performing Financing Receivable [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	1,913,387	1,711,503	$ 1,672,215
Performing Financing Receivable [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	332,207	256,225
Performing Financing Receivable [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	2,725,540	2,819,736
Performing Financing Receivable [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	656,836	642,734
Performing Financing Receivable [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	935,264	834,120
Performing Financing Receivable [Member] | Government-guaranteed mortgage loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	147,205	138,939
Nonperforming Financial Instruments [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	1,329	1,237
Nonperforming Financial Instruments [Member] | Other Loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	147,287	178,291
Nonperforming Financial Instruments [Member] | Other Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	7,865	5,370
Nonperforming Financial Instruments [Member] | Auto loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	11,212	10,211
Nonperforming Financial Instruments [Member] | Government-guaranteed mortgage loans [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	$ 0	$ 0