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Consolidated Statements of Income (Parenthetical) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Consolidated Statements of Income |  |  |
Impairment charges, other-than-temporary impairment charges | $ (366)iboc_OtherThanTemporaryImpairmentLossesInvestmentPortionRecognizedInEarningsNet | $ (431)iboc_OtherThanTemporaryImpairmentLossesInvestmentPortionRecognizedInEarningsNet | $ (916)iboc_OtherThanTemporaryImpairmentLossesInvestmentPortionRecognizedInEarningsNet
Impairment charges, other comprehensive (loss) income | $ 1,183 us-gaap_OtherComprehensiveIncomeLossBeforeTax | $ 1,805 us-gaap_OtherComprehensiveIncomeLossBeforeTax | $ (123)us-gaap_OtherComprehensiveIncomeLossBeforeTax

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- Definition The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of the amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting. + References No definition available. + Details
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- Details
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- Definition Amount before tax, after reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669619-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669625-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33775-111570 + Details
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