LOANS AND LEASES AND ALLOWANCE FOR LOAN AND LEASE LOSSES - Schedule of Loans and Leases Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 6,105,321	$ 6,034,752	$ 5,463,068
Allowance for loan and lease losses	(42,736)	(40,444)	(35,845)	$ (35,533)
Loans and leases receivable, net	6,062,585	5,994,308
Purchased Credit Impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	139,699	141,826	683,976
Allowance for loan and lease losses	(161)		(206)
Non-Traditional Mortgages (NTM)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	818,010	885,148
Traditional Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,147,612	5,007,778
Traditional Loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	142,164	125,100
Total NTM and Traditional Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,965,622	5,892,926
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,585,656	1,522,960	983,961
Allowance for loan and lease losses	(10,888)	(7,584)	(6,046)	(5,850)
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	750,592	729,959	713,693
Allowance for loan and lease losses	(4,543)	(5,467)	(3,969)	(4,252)
Commercial | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,449,715	1,365,262	1,021,097
Allowance for loan and lease losses	(11,029)	(11,376)	(6,484)	(6,012)
Commercial | SBA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	76,040	73,840	71,640
Allowance for loan and lease losses	(1,146)	(939)	(906)	(683)
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	142,164	125,100	68,241
Allowance for loan and lease losses	(3,018)	(2,015)	(1,520)	(1,530)
Commercial | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	285	379	212,836
Allowance for loan and lease losses	(5)	(6)	(2,610)	$ (2,195)
Commercial | Purchased Credit Impaired | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,687	4,760	819
Allowance for loan and lease losses	0		(58)
Commercial | Purchased Credit Impaired | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,152	1,182	8,218
Allowance for loan and lease losses	(5)		(112)
Commercial | Purchased Credit Impaired | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0	0
Allowance for loan and lease losses	0		0
Commercial | Purchased Credit Impaired | SBA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	2,607	2,672	2,940
Allowance for loan and lease losses	(19)		(19)
Commercial | Purchased Credit Impaired | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0	0
Allowance for loan and lease losses	0		0
Commercial | Purchased Credit Impaired | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0	0
Allowance for loan and lease losses	0		$ 0
Commercial | Non-Traditional Mortgages (NTM) | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Commercial | Non-Traditional Mortgages (NTM) | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Commercial | Non-Traditional Mortgages (NTM) | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Commercial | Non-Traditional Mortgages (NTM) | SBA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Commercial | Non-Traditional Mortgages (NTM) | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Commercial | Non-Traditional Mortgages (NTM) | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Commercial | Traditional Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,580,969	1,518,200
Commercial | Traditional Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	749,440	728,777
Commercial | Traditional Loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,449,715	1,365,262
Commercial | Traditional Loans | SBA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	73,433	71,168
Commercial | Traditional Loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	142,164	125,100
Commercial | Traditional Loans | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	285	379
Commercial | Total NTM and Traditional Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,580,969	1,518,200
Commercial | Total NTM and Traditional Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	749,440	728,777
Commercial | Total NTM and Traditional Loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,449,715	1,365,262
Commercial | Total NTM and Traditional Loans | SBA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	73,433	71,168
Commercial | Total NTM and Traditional Loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	142,164	125,100
Commercial | Total NTM and Traditional Loans | Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	285	379
Consumer | Single family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,889,390	2,019,161
Consumer | Home equity loan | Green Loans (HELOC) - first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	85,665	87,469
Consumer | Home equity loan | Green Loans (HELOC) - second liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,549	3,559
Consumer | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	122,265	107,063
Consumer | Purchased Credit Impaired | Single family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	131,253	133,212
Consumer | Purchased Credit Impaired | Home equity loan | Green Loans (HELOC) - first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Consumer | Purchased Credit Impaired | Home equity loan | Green Loans (HELOC) - second liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Consumer | Purchased Credit Impaired | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Consumer | Non-Traditional Mortgages (NTM)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	818,010	885,148
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	814,461	881,589
Consumer | Non-Traditional Mortgages (NTM) | Green Loans (HELOC) - second liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,549	3,559
Consumer | Non-Traditional Mortgages (NTM) | Single family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	728,796	794,120
Consumer | Non-Traditional Mortgages (NTM) | Home equity loan | Green Loans (HELOC) - first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	85,665	87,469
Consumer | Non-Traditional Mortgages (NTM) | Home equity loan | Green Loans (HELOC) - second liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,549	3,559
Consumer | Non-Traditional Mortgages (NTM) | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Consumer | Traditional Loans | Single family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,029,341	1,091,829
Consumer | Traditional Loans | Home equity loan | Green Loans (HELOC) - first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Consumer | Traditional Loans | Home equity loan | Green Loans (HELOC) - second liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Consumer | Traditional Loans | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	122,265	107,063
Consumer | Total NTM and Traditional Loans | Single family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,758,137	1,885,949
Consumer | Total NTM and Traditional Loans | Home equity loan | Green Loans (HELOC) - first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	85,665	87,469
Consumer | Total NTM and Traditional Loans | Home equity loan | Green Loans (HELOC) - second liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,549	3,559
Consumer | Total NTM and Traditional Loans | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 122,265	$ 107,063