LOAN PORTFOLIO - Breakdown Between Accrual and Nonaccrual Status of TDRs (Detail) - USD ($) $ in Thousands	Mar. 31, 2016		Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 659,104		$ 661,591		$ 705,123	$ 694,453
Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	245,671	[1]	246,683	[2]
Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	413,433		414,908
Non Fha Va Residential Mortgage Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			382,672
Non Fha Va Residential Mortgage Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	81,562	[1]	78,787	[2]
Non Fha Va Residential Mortgage Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	302,773		303,885
Commercial Mortgage Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			44,498
Commercial Mortgage Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	15,706	[1]	15,377	[2]
Commercial Mortgage Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	27,763		29,121
Commercial And Industrial Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			150,254
Commercial And Industrial Loan [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	97,365	[1]	101,862	[2]
Commercial And Industrial Loan [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	47,463		48,392
Consumer Auto Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			21,582
Consumer Auto Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,537	[1]	6,759	[2]
Consumer Auto Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	15,943		14,823
Finance Leases [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			2,077
Finance Leases [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	140	[1]	97	[2]
Finance Leases [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,329		1,980
Other Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			14,794
Other Consumer Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,129	[1]	2,057	[2]
Other Consumer Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	13,214		12,737
Commercial Construction [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			39,466
Commercial Construction [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	39,037	[1]	39,466	[2]
Commercial Construction [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0
Residential Construction [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			3,482
Residential Construction [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	357	[1]	436	[2]
Residential Construction [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,031		3,046
Land Construction [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment			2,766
Land Construction [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,838	[1]	1,842	[2]
Land Construction [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 917		$ 924

[1] Included in non-accrual loans are $119.2 million in loans that are performing under the terms of a restructuring agreement but are reported in non-accrual status until the restructured loans meet the criteria of sustained payment performance under the revised terms for reinstatement to accrual status and there is no doubt about full collectability.

[2] Included in non-accrual loans are $118.2 million in loans that are performing under the terms of a restructuring agreement but are reported in non-accrual status until the restructured loans meet the criteria of sustained payment performance under the revised terms for reinstatement to accrual status and there is no doubt about full collectability.