LOAN PORTFOLIO - Breakdown Between Accrual and Nonaccrual Status of TDRs (Detail) - USD ($) $ in Thousands	Sep. 30, 2016		Jun. 30, 2016	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 656,318		$ 670,991	$ 661,591		$ 681,963	$ 634,761	$ 694,453
Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	240,399	[1]		246,683	[2]
Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	415,919			414,908
Non Fha Va Residential Mortgage Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	378,721			382,672
Non Fha Va Residential Mortgage Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	81,881	[1]		78,787	[2]
Non Fha Va Residential Mortgage Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	296,840			303,885
Commercial Mortgage Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	43,972			44,498
Commercial Mortgage Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	15,273	[1]		15,377	[2]
Commercial Mortgage Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	28,699			29,121
Commercial And Industrial Loan [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	150,890			150,254
Commercial And Industrial Loan [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	92,886	[1]		101,862	[2]
Commercial And Industrial Loan [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	58,004			48,392
Consumer Auto Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	25,023			21,582
Consumer Auto Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	8,462	[1]		6,759	[2]
Consumer Auto Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	16,561			14,823
Finance Leases [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,576			2,077
Finance Leases [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	139	[1]		97	[2]
Finance Leases [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,437			1,980
Other Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	14,946			14,794
Other Consumer Loans [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,773	[1]		2,057	[2]
Other Consumer Loans [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	12,173			12,737
Commercial Construction [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	36,953			39,466
Commercial Construction [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	36,953	[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	357			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	0			3,046
Land Construction [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,880			2,766
Land Construction [Member] | Non Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,675	[1]		1,842	[2]
Land Construction [Member] | Accrual [Member]
Financing Receivable Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 1,205			$ 924

[1] Included in non-accrual loans are $121.3 million in loans that are performing under the terms of the 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 are deemed fully collectible.

[2] Included in non-accrual loans are $118.2 million in loans that are performing under the terms of the 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.