LOAN PORTFOLIO - Credit Risk Payment Activity (Detail) - USD ($) $ in Thousands	Mar. 31, 2016		Dec. 31, 2015		Mar. 31, 2015
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	$ 9,131,342		$ 9,273,865		$ 9,485,372
Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	904,334		934,980
Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	230,801		229,165
Residential Real Estate [Member] | Fhava Guaranteed Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	136,704	[1]	143,141	[2]
Residential Real Estate [Member] | Other Residential Mortgage Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	3,194,241		3,201,578
Residential Real Estate [Member] | Performing Financing Receivable [Member] | Fhava Guaranteed Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	136,704	[1]	143,141	[2]
Residential Real Estate [Member] | Performing Financing Receivable [Member] | Other Residential Mortgage Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	2,852,161		2,861,811
Residential Real Estate [Member] | Purchased Credit Impaired [Member] | Fhava Guaranteed Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	0	[1],[3]	0	[2],[4]
Residential Real Estate [Member] | Purchased Credit Impaired [Member] | Other Residential Mortgage Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	169,190	[3]	170,766	[4]
Residential Real Estate [Member] | Nonperforming Financing Receivable [Member] | Fhava Guaranteed Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	0	[1]	0	[2]
Residential Real Estate [Member] | Nonperforming Financing Receivable [Member] | Other Residential Mortgage Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	172,890		169,001
Consumer [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	904,334		934,980
Consumer [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	230,801		229,165
Consumer [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	651,226		663,004
Consumer [Member] | Performing Financing Receivable [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	889,296		917,545
Consumer [Member] | Performing Financing Receivable [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	228,665		226,706
Consumer [Member] | Performing Financing Receivable [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	641,049		652,146
Consumer [Member] | Purchased Credit Impaired [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	0	[3]	0	[4]
Consumer [Member] | Purchased Credit Impaired [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	0	[3]	0	[4]
Consumer [Member] | Purchased Credit Impaired [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	0	[3]	0	[4]
Consumer [Member] | Nonperforming Financing Receivable [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	15,038		17,435
Consumer [Member] | Nonperforming Financing Receivable [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	2,136		2,459
Consumer [Member] | Nonperforming Financing Receivable [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	$ 10,177		$ 10,858

[1] It is the Corporation's policy to report delinquent residential mortgage loans insured by the FHA or guaranteed by the VA as past-due loans 90 days and still accruing as opposed to non-performing loans since the principal repayment is insured. These balances include $34.9 million of residential mortgage loans insured by the FHA or guaranteed by the VA, which are over 15 months delinquent, and are no longer accruing interest as of March 31, 2016.

[2] It is the Corporation's policy to report delinquent residential mortgage loans insured by the FHA or guaranteed by the VA as past due loans 90 days and still accruing as opposed to non-performing loans since the principal repayment is insured. These balances include $37.3 million of residential mortgage loans insured by the FHA or guaranteed by the VA, which are over 15 months delinquent, and are no longer accruing interest as of December 31, 2015.

[3] PCI loans are excluded from non-performing statistics due to the application of the accretion method, under which these loans will accrete interest income over the remaining life of the loans using estimated cash flow analysis.

[4] PCI loans are excluded from non-performing statistics due to the application of the accretion method, under which these loans will accrete interest income over the remaining life of the loans using estimated cash flow analysis.