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Allowance for Probable Loan Losses (Details 3) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | $ 118,505 | $ 108,030 | $ 68,338
Reduced interest income on non-accrual loans | 4,114 | 3,750 | 4,011
Accruing loans contractually past due 90 days or more as to principal or interest payments | 14,288 | 19,848 | 12,089
Commercial |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 26,819 | 22,614 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 1,490 | 1,029 |
Commercial real estate: other construction and land development |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 54,336 | 77,207 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 979 | 11,507 |
Commercial real estate: farmland and commercial |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 34,910 | 5,486 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 1,231 | 1,585 |
Commercial real estate: multifamily |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 411 | 473 |
Residential: first lien |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 1,848 | 2,015 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 9,382 | 3,472 |
Residential: junior lien |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 135 | 199 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 320 | 277 |
Consumer |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 46 | 29 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 866 | 1,477 |
Foreign |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total |  | 7 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | $ 20 | $ 501 |

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- Definition Represents the reduction in interest income on recorded investment in financing receivables that are on nonaccrual status. + References No definition available. + Details
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- Definition Recorded investment in financing receivables that are 90 days or more past due and still accruing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5111-111524 -Subparagraph (d) + Details
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- Definition Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5111-111524 -Subparagraph (d) + Details
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