Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Valuation methodologies used for assets measured at fair value
Percentage of non performing loans held-for-sale comprising of multi family mortgage loans	60.00%
Percentage of non performing loans held-for-sale comprising residential mortgage loans	40.00%
Impaired loans comprising residential mortgage loans (as a percent)	75.00%	73.00%
Impaired loans comprising multi-family and commercial real estate loans (as a percent)	22.00%	25.00%
Impaired Loans comprising home equity lines of credit (as a percent)	3.00%	2.00%
Impaired loans for which fair value adjustment is recognized comprising residential mortgage loans (as a percent)	73.00%	69.00%
Impaired loans for which fair value adjustment is recognized comprising multi-family and commercial real estate loans (as a percent)	26.00%	30.00%
Impaired loans for which fair value adjustment is recognized comprising home equity lines of credit (as a percent)	1.00%	1.00%
Real estate owned, net	30,160	35,723
Weighted average
Valuation methodologies used for assets measured at fair value
Assumption to estimate fair value of servicing asset, weighted average discount rate (as a percent)	9.47%	9.48%
Assumption to estimate fair value of servicing asset, weighted average constant prepayment rate (as a percent)	13.35%	12.35%
Assumption to estimate fair value of servicing asset, weighted average life	5 years 4 months 24 days	5 years 8 months 11 days
Non Performing Multi Family Mortgage Loans
Valuation methodologies used for assets measured at fair value
Non-Performing Number Of Loans		1
Residential Mortgage Loans
Valuation methodologies used for assets measured at fair value
Period after which loans are individually evaluated for impairment	180 days
Period past due when loan servicer performs property inspections	45 days
Home equity lines of credit
Valuation methodologies used for assets measured at fair value
Period after which loans are individually evaluated for impairment	90 days
Residential Properties
Valuation methodologies used for assets measured at fair value
Real estate owned, net	28,100	33,700
Recurring basis \| Residential mortgage-backed securities
Valuation methodologies used for assets measured at fair value
Percentage of debt securities comprising available for sale securities portfolio	76.00%	75.00%
Percentage available for sale residential mortgage backed securities which are GSE securities	99.00%	98.00%
Recurring basis \| Obligations of GSEs
Valuation methodologies used for assets measured at fair value
Percentage of debt securities comprising available for sale securities portfolio	24.00%	25.00%

The past due period of time after which all loans are individually evaluated for impairment.

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Represents the period of time past due when loan servicer performs property inspections to monitor and manage collateral.

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- Definition

Non-Performing Number Of Loans

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- Definition

Percentage Of Available For Sale Residential Mortgage Backed Securities which are Government Sponsored Enterprise Securities.

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Percentage of debt securities comprising securities available-for-sale portfolio.

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Represents the percentage of impaired loans comprising home equity lines of credit.

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- Definition

Represents the percentage of impaired loans comprising multi-family and commercial real estate loans.

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- Definition

Represents the percentage of impaired loans comprising residential mortgage loans.

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Represents the percentage of impaired loans for which fair value adjustment is recognized, comprising home equity lines of credit.

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- Definition

Percentage Of Non Performing Loans Held-For-Sale Comprising Of Multi Family Mortgage Loans

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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4437-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule III

-Article 5

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- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 2

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122596-111746

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

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- Definition

Weighted average life of financial assets and financial liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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