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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, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | $ 71,768 | $ 118,505 | $ 108,030
Reduced interest income on non-accrual loans | 2,549 | 4,114 | 3,750
Accruing loans contractually past due 90 days or more as to principal or interest payments | 15,033 | 14,288 | 19,848
Commercial |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 31,929 | 26,819 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 2,689 | 1,490 |
Commercial real estate: other construction and land development |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 26,410 | 54,336 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 497 | 979 |
Commercial real estate: farmland and commercial |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 11,681 | 34,910 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 929 | 1,231 |
Commercial real estate: multifamily |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 353 | 411 |
Residential: first lien |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 1,175 | 1,848 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 9,657 | 9,382 |
Residential: junior lien |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 175 | 135 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 115 | 320 |
Consumer |  |  |
Loan loss allowances, financing receivable past due |  |  |
Non-accrual loans, total | 45 | 46 |
Accruing loans contractually past due 90 days or more as to principal or interest payments | 882 | 866 |
Foreign |  |  |
Loan loss allowances, financing receivable past due |  |  |
Accruing loans contractually past due 90 days or more as to principal or interest payments | $ 264 | $ 20 |

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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 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5111-111524 + 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 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5111-111524 + Details
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