LOAN PORTFOLIO - Credit Risk Payment Activity (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	$ 9,485,372		$ 9,262,436		$ 9,566,785
Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	1,028,370		1,060,782
Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	230,183		232,126
Residential Real Estate [Member] | Fhava Guaranteed Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	155,662	[1]	153,570	[2]
Residential Real Estate [Member] | Other Residential Mortgage Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	3,175,958		2,857,617
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	155,662	[1]	153,570	[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	2,825,774		2,578,416
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],[3]
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	177,601	[3]	98,494	[3]
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	172,583		180,707
Consumer [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	1,028,370		1,060,782
Consumer [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	230,183		232,126
Consumer [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	678,629		689,637
Consumer [Member] | Performing Financing Receivable [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	1,009,327		1,038,506
Consumer [Member] | Performing Financing Receivable [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	227,204		226,881
Consumer [Member] | Performing Financing Receivable [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	665,504		673,626
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	[3]
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	[3]
Consumer [Member] | Purchased Credit Impaired [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	234	[3]	717	[3]
Consumer [Member] | Nonperforming Financing Receivable [Member] | Auto loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	19,043		22,276
Consumer [Member] | Nonperforming Financing Receivable [Member] | Finance Leases [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	2,979		5,245
Consumer [Member] | Nonperforming Financing Receivable [Member] | Other Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans And Leases Receivable Gross Carrying Amount	$ 12,891		$ 15,294

[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 $30.1 million of residential mortgage loans insured by the FHA or guaranteed by the VA, which are over 18 months delinquent, and are no longer accruing interest as of March 31, 2015.

[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 $40.4 million of residential mortgage loans insured by the FHA or guaranteed by the VA, which are over 18 months delinquent, and are no longer accruing interest as of December 31, 2014.

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