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Allowance for Probable Loan Losses (Details 4) (USD $) | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 | Jun. 30, 2012 | Dec. 31, 2012
Interest Recognized |  |  |  |  |
Loans accounted for as troubled debt restructuring | $ 22,307,000 |  | $ 22,307,000 |  | $ 29,395,000
Period of charge off for past due unsecured commercial loans |  |  | 90 days |  |
Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with related allowance | 29,950,000 |  | 29,950,000 |  | 11,982,000
Total impaired loans with no related allowance | 56,348,000 |  | 56,348,000 |  | 71,023,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with an allowance recorded | 33,285,000 |  | 33,285,000 |  | 15,273,000
Total impaired loans with no related allowance recorded | 58,077,000 |  | 58,077,000 |  | 73,728,000
Related Allowance | 15,173,000 |  | 15,173,000 |  | 4,746,000
Average recorded investment: |  |  |  |  |
Total impaired loans with an allowance recorded | 29,022,000 | 64,403,000 | 29,670,000 | 71,543,000 | 35,076,000
Total impaired loans with no related allowance recorded | 52,443,000 | 51,564,000 | 50,697,000 | 53,909,000 | 65,536,000
Interest Recognized |  |  |  |  |
Total impaired loans with an allowance recorded | 33,000 | 23,000 | 67,000 | 56,000 | 131,000
Total impaired loans with no related allowance recorded | 86,000 | 81,000 | 167,000 | 179,000 | 323,000
Commercial | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with related allowance | 18,170,000 |  | 18,170,000 |  | 1,633,000
Total impaired loans with no related allowance | 16,950,000 |  | 16,950,000 |  | 31,135,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with an allowance recorded | 18,170,000 |  | 18,170,000 |  | 1,679,000
Total impaired loans with no related allowance recorded | 17,580,000 |  | 17,580,000 |  | 31,170,000
Related Allowance | 10,961,000 |  | 10,961,000 |  | 1,477,000
Average recorded investment: |  |  |  |  |
Total impaired loans with an allowance recorded | 18,174,000 | 24,271,000 | 18,184,000 | 24,417,000 | 21,126,000
Total impaired loans with no related allowance recorded | 17,309,000 | 3,798,000 | 16,475,000 | 3,808,000 | 2,996,000
Interest Recognized |  |  |  |  |
Total impaired loans with an allowance recorded | 10,000 |  | 21,000 | 10,000 | 39,000
Total impaired loans with no related allowance recorded |  | 1,000 |  | 1,000 | 4,000
Commercial real estate: other construction and land development | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with related allowance | 3,968,000 |  | 3,968,000 |  | 3,671,000
Total impaired loans with no related allowance | 22,522,000 |  | 22,522,000 |  | 24,989,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with an allowance recorded | 3,971,000 |  | 3,971,000 |  | 3,671,000
Total impaired loans with no related allowance recorded | 22,611,000 |  | 22,611,000 |  | 25,160,000
Related Allowance | 766,000 |  | 766,000 |  | 539,000
Average recorded investment: |  |  |  |  |
Total impaired loans with an allowance recorded | 3,969,000 | 27,377,000 | 4,820,000 | 33,384,000 | 6,608,000
Total impaired loans with no related allowance recorded | 20,217,000 | 29,816,000 | 20,451,000 | 31,627,000 | 39,449,000
Interest Recognized |  |  |  |  |
Total impaired loans with no related allowance recorded | 18,000 | 41,000 | 37,000 | 99,000 | 141,000
Commercial real estate: farmland and commercial | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with related allowance | 7,812,000 |  | 7,812,000 |  | 6,678,000
Total impaired loans with no related allowance | 8,786,000 |  | 8,786,000 |  | 7,267,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with an allowance recorded | 11,144,000 |  | 11,144,000 |  | 9,923,000
Total impaired loans with no related allowance recorded | 9,648,000 |  | 9,648,000 |  | 9,340,000
Related Allowance | 3,446,000 |  | 3,446,000 |  | 2,730,000
Average recorded investment: |  |  |  |  |
Total impaired loans with an allowance recorded | 6,879,000 | 12,553,000 | 6,666,000 | 13,539,000 | 7,342,000
Total impaired loans with no related allowance recorded | 6,579,000 | 11,545,000 | 5,793,000 | 11,996,000 | 16,536,000
Interest Recognized |  |  |  |  |
Total impaired loans with an allowance recorded | 23,000 | 23,000 | 46,000 | 46,000 | 92,000
Total impaired loans with no related allowance recorded |  |  |  | 8,000 | 8,000
Commercial real estate: multifamily | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with no related allowance | 324,000 |  | 324,000 |  | 353,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with no related allowance recorded | 324,000 |  | 324,000 |  | 353,000
Average recorded investment: |  |  |  |  |
Total impaired loans with no related allowance recorded | 329,000 | 387,000 | 337,000 | 394,000 | 381,000
Residential: first lien | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with no related allowance | 4,367,000 |  | 4,367,000 |  | 3,656,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with no related allowance recorded | 4,490,000 |  | 4,490,000 |  | 3,984,000
Average recorded investment: |  |  |  |  |
Total impaired loans with an allowance recorded |  | 202,000 |  | 203,000 |
Total impaired loans with no related allowance recorded | 4,605,000 | 2,681,000 | 4,222,000 | 2,596,000 | 2,876,000
Interest Recognized |  |  |  |  |
Total impaired loans with no related allowance recorded | 39,000 | 11,000 | 72,000 | 16,000 | 60,000
Residential: junior lien | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with no related allowance | 1,711,000 |  | 1,711,000 |  | 1,850,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with no related allowance recorded | 1,729,000 |  | 1,729,000 |  | 1,944,000
Average recorded investment: |  |  |  |  |
Total impaired loans with no related allowance recorded | 1,713,000 | 2,113,000 | 1,722,000 | 2,119,000 | 1,939,000
Interest Recognized |  |  |  |  |
Total impaired loans with no related allowance recorded | 24,000 | 27,000 | 49,000 | 54,000 | 104,000
Consumer | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with no related allowance | 1,239,000 |  | 1,239,000 |  | 1,326,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with no related allowance recorded | 1,244,000 |  | 1,244,000 |  | 1,330,000
Average recorded investment: |  |  |  |  |
Total impaired loans with no related allowance recorded | 1,236,000 | 1,178,000 | 1,241,000 | 1,323,000 | 1,193,000
Foreign | Class of financing receivable |  |  |  |  |
Recorded investment: |  |  |  |  |
Total impaired loans with no related allowance | 449,000 |  | 449,000 |  | 447,000
Unpaid principal balance: |  |  |  |  |
Total impaired loans with no related allowance recorded | 451,000 |  | 451,000 |  | 447,000
Average recorded investment: |  |  |  |  |
Total impaired loans with no related allowance recorded | 455,000 | 45,000 | 456,000 | 45,000 | 166,000
Interest Recognized |  |  |  |  |
Total impaired loans with no related allowance recorded | $ 5,000 | $ 1,000 | $ 9,000 | $ 1,000 | $ 6,000

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