Loans (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010
Deteriorated Loans Transferred in [Abstract]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	$ 26,442	$ 35,887
Certain Loans Acquired in Transfer not Accounted for as Debt Securities Carrying Amount Accretion	26,442	35,887
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	11,813	21,246
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities F D I C Payments Received under Loss Sharing Agreement	111,901	122,946
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Disposals of Loans	815	565
Contractual Required Payments Receivable [Abstract]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,515,024	1,954,383	1,600,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications to Nonaccretable Difference	(310,213)	(316,179)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition	1,204,811	1,638,204
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield	(161,292)	(212,446)	(176,736)	(227,652)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 1,043,519	$ 1,425,758	$ 1,128,978	$ 1,512,817

CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountAccretion.

No definition available.

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- Definition

Certain Loans Acquired In Transfer Not Accounted For As Debt Securities FDIC Payments Received Under Loss Sharing Agreement.

+ References

No definition available.

+ Details

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- Definition

The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 03-3

-Paragraph 16

-Subparagraph a(2)

-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 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6891207&loc=d3e13503-111538

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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- Definition

The current period recognition due to accretion of the excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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- Definition

The sale or transfer of a loan during the period resulting in a reduction in the excess of a loan's cash flows expected to be collected over the investor's initial investment. This relates to loans not accounted for as a debt security, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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- Definition

The change in the estimate of cash flows expected to be collected, after acquisition of loans, which results in an increase in accretable yield (for example, if actual cash flows are significantly greater than previously expected). This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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- Definition

The change in the estimate of cash flows expected to be collected, after acquisition of a loan, which results in a decrease in accretable yield (for example, if it is probable that expected cash flows will be less than previously expected). This relates to loans not accounted for as a debt security, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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- Definition

The investor's estimate, at acquisition, of the amount and timing of undiscounted principal, interest, and other cash flows expected to be collected. This would be the investor's best estimate of cash flows, including the effect of prepayments if considered, that is used in determining the acquisition price, and, in a business combination, the investor's estimate of fair value for purposes of acquisition price allocation. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 03-3

-Paragraph 16

-Subparagraph a(3)

-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 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6891207&loc=d3e13503-111538

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 03-3

-Paragraph 16

-Subparagraph a(1)

-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 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6891207&loc=d3e13503-111538

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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- Definition

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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