LOAN PORTFOLIO - Selected Information on TDRs Includes Recorded Investment by Loan Class and Modification Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2016		Jun. 30, 2016	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 656,318		$ 670,991	$ 661,591		$ 681,963	$ 634,761	$ 694,453
Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	38,408			35,697
Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	83,450			87,159
Combination of reduction in interest rate and extension of maturity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	364,011			380,714
Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	39,890			42,820
Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	130,559	[1]		115,201	[2]
Non Fha Va Residential Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	378,721			382,672
Non Fha Va Residential Mortgage Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	29,934			29,066
Non Fha Va Residential Mortgage Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	8,172			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	283,550			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	57,065	[1]		50,269	[2]
Commercial Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	43,972			44,498
Commercial Mortgage Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	6,092			4,379
Commercial Mortgage Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,219			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	26,053			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	10,608	[1]		12,766	[2]
Commercial And Industrial Loan [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	150,890			150,254
Commercial And Industrial Loan [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,153			2,163
Commercial And Industrial Loan [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	69,244			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	25,263			27,214
Commercial And Industrial Loan [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,637			3,027
Commercial And Industrial Loan [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	51,593	[1]		42,746	[2]
Construction Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	40,200
Consumer Auto Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	25,023			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	1,921			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	14,680			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	8,422	[1]		6,864	[2]
Finance Leases [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,576			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	424			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	2,152			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	14,946			14,794
Other Consumer Loans [Member] | Interest Rate Below Market [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	229			89
Other Consumer Loans [Member] | Maturity of Term Extension [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,185			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	10,120			11,026
Other Consumer Loans [Member] | Forgiveness of principal and/or interest [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	300			327
Other Consumer Loans [Member] | Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,112	[1]		1,748	[2]
Commercial Construction [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Modifications, Recorded Investment	36,953			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	36,953			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	357			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	0			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	2,880			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	285			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	2,193			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	$ 402	[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.