Securities (Details Textual) (USD $)	9 Months Ended	12 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Securities (Textual) [Abstract]
Impairment loss recognized	$ 0		$ 0
Sales of mortgage-backed securities available for sale	8,960,000,000	1,900,000,000
Realized gains on sale of mortgage-backed securities available for sale	100,000,000	92,400,000
Sales of investment securities available-for-sale or held to maturity		0
Sales of investment securities available-for-sale	80,000,000
Gross realized gains on sales and calls of investment securities available for sale	$ 2,500,000

Gross realized gains on sales and calls of investment securities available for sale.

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- Definition

Impairment loss recognized.

+ Details

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- Definition

Principle amount of investment securities available for sale.

+ Details

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- Definition

Sales of mortgage-backed securities available for sale.

+ Details

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- Definition

Securities Textual.

+ Details

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- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 21

-Subparagraph a

+ Details

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- Definition

The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 21

-Subparagraph a

+ Details

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