Fair Value Measurements (Details) (Recurring basis, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value of Financial Instruments
Total securities available-for-sale	$ 336,300	$ 344,187
Residential mortgage-backed securities
Fair Value of Financial Instruments
Percentage of debt securities comprising available-for-sale portfolio	71.00%	99.00%
Available-for-sale residential mortgage-backed securities portfolio which are GSE securities (as a percent)	95.00%
GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	204,827	298,620
Residential mortgage-backed securities portfolio which are REMICs and CMOs of which estimated fair values are reviewed every month (as a percent)	90.00%
Non-GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	11,219	15,795
GSE pass-through certificates
Fair Value of Financial Instruments
Total securities available-for-sale	21,375	25,192
Obligations of GSEs
Fair Value of Financial Instruments
Total securities available-for-sale	98,879
Percentage of debt securities comprising available-for-sale portfolio	29.00%
Freddie Mac and Fannie Mae stock
Fair Value of Financial Instruments
Total securities available-for-sale		4,580
Level 1
Fair Value of Financial Instruments
Total securities available-for-sale		4,580
Level 1 \| Freddie Mac and Fannie Mae stock
Fair Value of Financial Instruments
Total securities available-for-sale		4,580
Level 2
Fair Value of Financial Instruments
Total securities available-for-sale	336,300	339,607
Level 2 \| GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	204,827	298,620
Level 2 \| Non-GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	11,219	15,795
Level 2 \| GSE pass-through certificates
Fair Value of Financial Instruments
Total securities available-for-sale	21,375	25,192
Level 2 \| Obligations of GSEs
Fair Value of Financial Instruments
Total securities available-for-sale	$ 98,879

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details