Deposits (Details) [Textuals] (USD $)	Jun. 30, 2011	Dec. 31, 2010
Deposits (Textuals) [Abstract]
Certificates of deposit in the amount of $100,000 or more	$ 1,800,000,000	$ 1,700,000,000
Certificates of deposit in the amount of $250,000 or more	290,300,000	266,700,000
Deposits insured up to the maximum limit by FDIC	$ 4,785,790,000	$ 4,621,273,000
Weighted-average interest rates for savings and money market deposit accounts	0.84%	0.83%
Weighted-average interest rates for certificates of deposit	1.21%	1.27%
Weighted-average interest rates for all deposits	1.13%	1.18%

Deposits.

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- Definition

The aggregate amount of domestic certificates of deposit in denominations of $250,000 or more.

+ Details

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- Definition

The weighted average interest rate for domestic savings and money market deposit accounts.

+ Details

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- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 12
-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-DEP
-Chapter 13
-Paragraph 37, 38, 39
-IssueDate 2006-05-01
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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- Definition

The aggregate amount of domestic time deposits (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 14
-Subparagraph e
-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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6479006&loc=d3e64164-112818

+ Details

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- Definition

The weighted average interest rate for all domestic deposit liabilities.

+ Details

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- Definition

The weighted average interest rate for domestic certificates of deposit liabilities.

+ Details

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