Loans and Allowance for Loan Losses - Company's Impaired Loans (Detail) (USD $) | 6 Months Ended | 12 Months Ended |
In Thousands, unless otherwise specified | Jun. 30, 2014 | Dec. 31, 2013 |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | $20,250 | $27,025 |
Unpaid Principal Balance | 22,191 | 28,887 |
Related Allowance | 3,148 | 4,516 |
Average Recorded Investment | 20,502 | 34,629 |
Interest Income Recognized | 232 | 755 |
With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 10,363 | 9,590 |
Unpaid Principal Balance | 10,385 | 9,602 |
Related Allowance | ' | ' |
Average Recorded Investment | 10,267 | 9,679 |
Interest Income Recognized | 78 | 287 |
With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 9,887 | 17,435 |
Unpaid Principal Balance | 11,806 | 19,285 |
Related Allowance | 3,148 | 4,516 |
Average Recorded Investment | 10,235 | 24,950 |
Interest Income Recognized | 154 | 468 |
Residential 1-4 Family [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 2,452 | 4,329 |
Unpaid Principal Balance | 2,661 | 4,590 |
Related Allowance | 665 | 1,150 |
Average Recorded Investment | 2,332 | 8,054 |
Interest Income Recognized | 56 | 203 |
Residential 1-4 Family [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 1,018 | 357 |
Unpaid Principal Balance | 1,008 | 404 |
Related Allowance | ' | ' |
Average Recorded Investment | 784 | 2,947 |
Interest Income Recognized | 30 | 16 |
Residential 1-4 Family [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 1,434 | 3,972 |
Unpaid Principal Balance | 1,653 | 4,186 |
Related Allowance | 665 | 1,150 |
Average Recorded Investment | 1,548 | 5,107 |
Interest Income Recognized | 26 | 187 |
Multifamily [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Multifamily [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Multifamily [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Construction [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 3,230 | 3,806 |
Unpaid Principal Balance | 3,293 | 3,806 |
Related Allowance | 950 | 950 |
Average Recorded Investment | 3,762 | 8,124 |
Interest Income Recognized | 9 | 11 |
Construction [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 812 | 1,393 |
Unpaid Principal Balance | 866 | 1,393 |
Related Allowance | ' | ' |
Average Recorded Investment | 1,346 | 2,265 |
Interest Income Recognized | ' | 11 |
Construction [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 2,418 | 2,413 |
Unpaid Principal Balance | 2,427 | 2,413 |
Related Allowance | 950 | 950 |
Average Recorded Investment | 2,416 | 5,859 |
Interest Income Recognized | 9 | ' |
Farmland [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 830 | 131 |
Unpaid Principal Balance | 829 | 131 |
Related Allowance | 263 | 57 |
Average Recorded Investment | 831 | 1,818 |
Interest Income Recognized | 4 | 8 |
Farmland [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Farmland [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 830 | 131 |
Unpaid Principal Balance | 829 | 131 |
Related Allowance | 263 | 57 |
Average Recorded Investment | 831 | 1,818 |
Interest Income Recognized | 4 | 8 |
Equity Lines of Credit [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | 174 |
Unpaid Principal Balance | ' | 174 |
Related Allowance | ' | 10 |
Average Recorded Investment | ' | 175 |
Interest Income Recognized | ' | 9 |
Equity Lines of Credit [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Equity Lines of Credit [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | 174 |
Unpaid Principal Balance | ' | 174 |
Related Allowance | ' | 10 |
Average Recorded Investment | ' | 175 |
Interest Income Recognized | ' | 9 |
Commercial [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | 52 |
Interest Income Recognized | ' | ' |
Commercial [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | 52 |
Interest Income Recognized | ' | ' |
Commercial [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Agricultural [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Agricultural [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Agricultural [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | ' |
Unpaid Principal Balance | ' | ' |
Related Allowance | ' | ' |
Average Recorded Investment | ' | ' |
Interest Income Recognized | ' | ' |
Commercial Real Estate [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 13,738 | 17,823 |
Unpaid Principal Balance | 15,408 | 19,425 |
Related Allowance | 1,270 | 2,300 |
Average Recorded Investment | 13,274 | 15,584 |
Interest Income Recognized | 163 | 524 |
Commercial Real Estate [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 8,533 | 7,234 |
Unpaid Principal Balance | 8,511 | 7,199 |
Related Allowance | ' | ' |
Average Recorded Investment | 7,834 | 3,750 |
Interest Income Recognized | 48 | 260 |
Commercial Real Estate [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | 5,205 | 10,589 |
Unpaid Principal Balance | 6,897 | 12,226 |
Related Allowance | 1,270 | 2,300 |
Average Recorded Investment | 5,440 | 11,834 |
Interest Income Recognized | 115 | 264 |
Second Mortgages [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | 762 |
Unpaid Principal Balance | ' | 761 |
Related Allowance | ' | 49 |
Average Recorded Investment | 303 | 822 |
Interest Income Recognized | ' | ' |
Second Mortgages [Member] | With No Related Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | 606 |
Unpaid Principal Balance | ' | 606 |
Related Allowance | ' | ' |
Average Recorded Investment | 303 | 665 |
Interest Income Recognized | ' | ' |
Second Mortgages [Member] | With Allowance Recorded [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Recorded Investment | ' | 156 |
Unpaid Principal Balance | ' | 155 |
Related Allowance | ' | 49 |
Average Recorded Investment | ' | 157 |
Interest Income Recognized | ' | ' |