Capital (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Capital [Line Items]
Risk Based Capital Required	$ 444,311	$ 488,754
Risk Based Capital Actual	5,163,442	4,759,331
Regulatory Capital Ratio, Required	4.00%	4.00%
Regulatory Capital Ratio, Actual	5.95%	5.84%
Regulatory Capital, Required	3,469,161	3,262,486
Regulatory Capital, Actual	5,163,442	4,759,331
Leverage Ratio, Required	5.00%	5.00%
Leverage Ratio, Actual	8.93%	8.75%
Leverage Capital, Required	4,336,451	4,078,108
Leverage Capital, Actual	7,745,163	7,138,997
Retained Earnings, Appropriated	$ 71,330	$ 58,628

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An entity's leverage capital amount as defined in the regulations.

+ References

No definition available.

+ Details

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- Definition

Leverage capital requirement as defined in the regulations.

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- Definition

An entity's leverage ratio as defined in the regulations.

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- Definition

Leverage ratio requirement as defined in the regulations.

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- Definition

An entity's regulatory capital amount as defined in the regulations.

+ References

No definition available.

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- Definition

An entity's regulatory capital ratio as defined in the regulations.

+ References

No definition available.

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- Definition

Regulatory capital ratio requirement as defined in the regulations.

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Regulatory capital requirement as defined in the regulations.

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- Definition

An entity's risk-based capital amount as defined in the regulations.

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No definition available.

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Risk-based capital requirement as defined in the regulations.

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- Definition

A segregation of retained earnings which is unavailable for dividend distribution. Includes also retained earnings appropriated for loss contingencies.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.23(4))

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-Number 210

-Section 03

-Paragraph 24

-Subparagraph a(4)

-Article 7

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-Name Regulation S-X (SX)

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-Publisher FASB

-Name Accounting Standards Codification

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-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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