ALLOWANCE FOR LOAN LOSSES AND RESERVE FOR FIRST LOSS POSITION ON MULTIFAMILY LOANS SOLD TO FNMA (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses at Period End on Substandard Non Impaired Loans	$ 100				$ 53
Increase (Decrease) in the balance of Substandard non-impaired loans	540
Financing Receivable Special Mention Allowance For Loan Losses period end balance	231				185
Financing Receivable Special Mention Balance Increase (Decrease)	790
Reserve For First Loss Position [Abstract]
Outstanding balance of multifamily loans serviced for FNMA at period end	0		244,159
First Loss Position Loans Serviced For Fnma	0		15,428
Reserve Liability On The First Loss Position [Roll Forward]
Balance at beginning of period	1,040		1,383
Credit for losses on problem loans(1)	(1,040)	[1]	(92)	[1]
Balance at period end	0		1,291
One To Four Family Residential And Cooperative Unit Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	236		344
Provision (credit) for loan losses	49		92
Charge-offs	(9)		(88)
Recoveries	1		2
Ending balance	277		350
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	930				1,199
Ending balance - loans collectively evaluated for impairment	75,842				72,757
Allowance balance associated with loans individually evaluated for impairment	0				0
Allowance balance associated with loans collectivelly evaluated for impairment	277				236
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	973				1,066
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0				255
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	930	[2]			987	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[2]			212	[2]
Impaired Financing Receivables With No Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivables With Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	959		629
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	106		212
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	15		15
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		5
Multifamily Residential And Residential Mixed Use Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	13,840		14,299
Provision (credit) for loan losses	338		(298)
Charge-offs	(37)		(111)
Recoveries	170		0
Ending balance	14,311		13,890
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	2,408				2,345
Ending balance - loans collectively evaluated for impairment	3,173,721				2,920,205
Allowance balance associated with loans individually evaluated for impairment	0				0
Allowance balance associated with loans collectivelly evaluated for impairment	14,311				13,840
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,408				2,494
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0				0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	2,408	[2]			2,345	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[2]			0	[2]
Impaired Financing Receivables With No Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivables With Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,377		4,787
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0		0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	22		49
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0
Commercial Mixed Use Real Estate Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,003		2,474
Provision (credit) for loan losses	(206)		87
Charge-offs	(30)		0
Recoveries	0		29
Ending balance	2,767		2,590
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	4,400				4,400
Ending balance - loans collectively evaluated for impairment	303,403				371,510
Allowance balance associated with loans individually evaluated for impairment	1,320				1,320
Allowance balance associated with loans collectivelly evaluated for impairment	1,447				1,683
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0				0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	4,500				4,500
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	[2]			0	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	4,400	[2]			4,400	[2]
Impaired Financing Receivables With No Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivables With Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	1,320				1,320
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		1,459
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	4,400		0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0		12
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0
Total Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	20,129		20,523
Provision (credit) for loan losses	281		152
Charge-offs	(184)		(203)
Recoveries	178		32
Ending balance	20,404		20,504
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	29,902				30,189
Ending balance - loans collectively evaluated for impairment	3,913,619				3,667,191
Allowance balance associated with loans individually evaluated for impairment	1,739				1,771
Allowance balance associated with loans collectivelly evaluated for impairment	18,665				18,358
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	11,688				11,876
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	19,470				19,797
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	10,532	[2]			10,535	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	19,370	[2]			19,654	[2]
Impaired Financing Receivables With No Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivables With Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	1,739				1,771
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	10,534		40,471
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	19,512		15,496
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	222		480
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	31		194
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	24		27
Provision (credit) for loan losses	1		5
Charge-offs	0		(6)
Recoveries	0		0
Ending balance	25		26
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	0				0
Ending balance - loans collectively evaluated for impairment	1,873				2,139
Allowance balance associated with loans individually evaluated for impairment	0				0
Allowance balance associated with loans collectivelly evaluated for impairment	25				24
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,047		3,382
Provision (credit) for loan losses	102		273
Charge-offs	(108)		(4)
Recoveries	7		1
Ending balance	3,048		3,652
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	22,164				22,245
Ending balance - loans collectively evaluated for impairment	360,431				302,451
Allowance balance associated with loans individually evaluated for impairment	419				451
Allowance balance associated with loans collectivelly evaluated for impairment	2,629				2,596
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	8,307				8,316
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	14,970				15,042
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,194	[2]			7,203	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	14,970	[2]			15,042	[2]
Impaired Financing Receivables With No Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivables With Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	419				451
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	7,198		33,596
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	15,006		15,284
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	185		404
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	31		189
Construction Loan Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3		24
Provision (credit) for loan losses	(2)		(2)
Charge-offs	0		0
Recoveries	0		0
Ending balance	1		22
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Ending balance - loans individually evaluated for impairment	0				0
Ending balance - loans collectively evaluated for impairment	222				268
Allowance balance associated with loans individually evaluated for impairment	0				0
Allowance balance associated with loans collectivelly evaluated for impairment	1				3
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0				0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0				0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	[2]			0	[2]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[2]			0	[2]
Impaired Financing Receivables With No Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivables With Allocated Reserves Within Allowance For Loan Losses Recognized For Impaired Receivables	0				0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0		0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0		0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	$ 0		$ 0

[1] Amount recognized as a component of mortgage banking income during the period.

[2] The recorded investment excludes accrued interest receivable and loan origination fees, net, due to immateriality.