LOAN PORTFOLIO - Selected Information on TDRs Includes Recorded Investment by Loan Class and Modification Type (Detail) - USD ($) $ in Thousands	Mar. 31, 2016		Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 659,104		$ 661,591		$ 705,123	$ 694,453
Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	35,392		35,697
Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	85,093		87,159
Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	381,063		380,714
Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	42,313		42,820
Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	115,243	[1]	115,201	[2]
Non Fha Va Residential Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	384,335		382,672
Non Fha Va Residential Mortgage Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	29,605		29,066
Non Fha Va Residential Mortgage Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	6,272		6,027
Non Fha Va Residential Mortgage Loans [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	296,531		297,310
Non Fha Va Residential Mortgage Loans [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Non Fha Va Residential Mortgage Loans [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	51,927	[1]	50,269	[2]
Commercial Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	43,469		44,498
Commercial Mortgage Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	4,005		4,379
Commercial Mortgage Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,235		1,244
Commercial Mortgage Loans [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	25,921		26,109
Commercial Mortgage Loans [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Commercial Mortgage Loans [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	12,308	[1]	12,766	[2]
Commercial And Industrial Loan [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	144,828		150,254
Commercial And Industrial Loan [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,700		2,163
Commercial And Industrial Loan [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	73,089		75,104
Commercial And Industrial Loan [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	26,583		27,214
Commercial And Industrial Loan [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,018		3,027
Commercial And Industrial Loan [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	40,438	[1]	42,746	[2]
Construction Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	45,200
Consumer Auto Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	23,480		21,582
Consumer Auto Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Consumer Auto Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,173		2,330
Consumer Auto Loans [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	13,765		12,388
Consumer Auto Loans [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Consumer Auto Loans [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,542	[1]	6,864	[2]
Finance Leases [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,469		2,077
Finance Leases [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Finance Leases [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	541		621
Finance Leases [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,928		1,456
Finance Leases [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Finance Leases [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	[1]	0	[2]
Other Consumer Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	15,343		14,794
Other Consumer Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	82		89
Other Consumer Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,555		1,604
Other Consumer Loans [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	11,145		11,026
Other Consumer Loans [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	258		327
Other Consumer Loans [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,303	[1]	1,748	[2]
Commercial Construction [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	39,037		39,466
Commercial Construction [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Commercial Construction [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Commercial Construction [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Commercial Construction [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	39,037		39,466
Commercial Construction [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	[1]	0	[2]
Residential Construction [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,388		3,482
Residential Construction [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Residential Construction [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Residential Construction [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,031		3,046
Residential Construction [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Residential Construction [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	357	[1]	436	[2]
Land Construction [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,755		2,766
Land Construction [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Land Construction [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	228		229
Land Construction [Member] | Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,159		2,165
Land Construction [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Land Construction [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 368	[1]	$ 372	[2]

[1] Other concessions granted by the Corporation include deferral of principal and/or interest payments for a period longer than what would be considered insignificant, payment plans under judicial stipulation, or a combination of the concessions listed in the table.

[2] Other concessions granted by the Corporation include deferral of principal and/or interest payments for a period longer than what would be considered insignificant, payment plans under judicial stipulation or a combination of the concessions listed in the table.