LOANS AND LEASES AND ALLOWANCE FOR LOAN AND LEASE LOSSES - Non Traditional Mortgage Performance Loan to Value Ratio (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017 USD ($) Loan	Dec. 31, 2016 USD ($) Loan	Mar. 31, 2016 USD ($)
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 6,105,321	$ 6,034,752	$ 5,463,068
Non-Traditional Mortgages (NTM)
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 818,010	$ 885,148
Consumer | Non-Traditional Mortgages (NTM)
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	607	663
Loans	$ 818,010	$ 885,148
Consumer | Non-Traditional Mortgages (NTM) | Green Loans
Financing Receivable, Recorded Investment [Line Items]
Loans	89,200	91,000
Consumer | Non-Traditional Mortgages (NTM) | Interest Only Loans
Financing Receivable, Recorded Investment [Line Items]
Loans	725,000	784,400
Consumer | Non-Traditional Mortgages (NTM) | Negative amortization
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 3,800	$ 9,800
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	595	651
Loans	$ 814,461	$ 881,589
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	100.00%	100.00%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Green Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	104	107
Loans	$ 85,665	$ 87,469
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	100.00%	100.00%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Interest Only Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	480	522
Loans	$ 725,005	$ 784,364
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	100.00%	100.00%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Negative amortization
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	11	22
Loans	$ 3,791	$ 9,756
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	100.00%	100.00%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	251	257
Loans	$ 374,753	$ 382,892
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	46.00%	43.40%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Green Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	56	45
Loans	$ 50,161	$ 39,105
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	58.60%	44.70%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Interest Only Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	187	196
Loans	$ 321,875	$ 336,744
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	44.40%	42.90%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Negative amortization
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	8	16
Loans	$ 2,717	$ 7,043
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Less than 61 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	71.70%	72.20%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	322	364
Loans	$ 421,544	$ 478,714
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	51.70%	54.30%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Green Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	41	52
Loans	$ 30,451	$ 41,732
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	35.50%	47.70%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Interest Only Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	278	306
Loans	$ 390,019	$ 434,269
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	53.80%	55.40%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Negative amortization
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	3	6
Loans	$ 1,074	$ 2,713
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 61-80 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	28.30%	27.80%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	14	18
Loans	$ 15,070	$ 15,460
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	1.90%	1.80%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Green Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	7	10
Loans	$ 5,053	$ 6,632
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	5.90%	7.60%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Interest Only Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	7	8
Loans	$ 10,017	$ 8,828
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	1.40%	1.10%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Negative amortization
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	0	0
Loans	$ 0	$ 0
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | 81-100 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	0.00%	0.00%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	8	12
Loans	$ 3,094	$ 4,523
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	0.40%	0.50%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Green Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	0	0
Loans	$ 0	$ 0
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	0.00%	0.00%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Interest Only Loans
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	8	12
Loans	$ 3,094	$ 4,523
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	0.40%	0.60%
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Negative amortization
Financing Receivable, Recorded Investment [Line Items]
Count | Loan	0	0
Loans	$ 0	$ 0
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens | Greater than 100 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio
Financing Receivable, Recorded Investment [Line Items]
Concentration risk percentage	0.00%	0.00%