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Capital Requirements (Capital Amounts and Ratios) (Details) - USD ($) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Jan. 01, 2016 | Jul. 31, 2013
Capital Requirements |  |  |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) |  | 2.50% | 0.625% |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) |  |  |  | 6.00%
Term of mandatory compliance |  | 4 years |  |
Minimum |  |  |  |
Capital Requirements |  |  |  |
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent) |  | 4.50% |  |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) |  |  |  | 4.00%
Parent Company |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount | $ 1,468,662 | $ 1,380,801 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 16.95% | 16.81% |  |
Total Capital (to Risk Weighted Assets), Actual Amount | $ 1,687,501 | $ 1,605,419 |  |
Tier 1 Capital (to Risk Weighted Assets), Actual Amount | 1,618,935 | 1,535,443 |  |
Tier 1 Capital (to Average Assets), Actual Amount | $ 1,618,935 | $ 1,535,443 |  |
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 19.47% | 19.54% |  |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 18.68% | 18.69% |  |
Tier 1 capital (to Average Assets), Actual Ratio (as a percent) | 13.91% | 13.15% |  |
Parent Company | Minimum |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 390,021 | $ 369,726 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 5.125% | 4.50% |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 693,370 | $ 657,291 |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | 520,028 | 492,968 |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount | $ 471,135 | $ 466,897 |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 8.625% | 8.00% |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 6.625% | 6.00% |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent) | 4.00% | 4.00% |  |
International Bank of Commerce, Laredo |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount | $ 1,201,527 | $ 1,151,812 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 16.63% | 16.42% |  |
Total Capital (to Risk Weighted Assets), Actual Amount | $ 1,260,886 | $ 1,213,377 |  |
Tier 1 Capital (to Risk Weighted Assets), Actual Amount | 1,201,527 | 1,151,812 |  |
Tier 1 Capital (to Average Assets), Actual Amount | $ 1,201,527 | $ 1,151,812 |  |
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 17.45% | 17.30% |  |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 16.63% | 16.42% |  |
Tier 1 capital (to Average Assets), Actual Ratio (as a percent) | 12.50% | 12.09% |  |
International Bank of Commerce, Laredo | Minimum |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 325,178 | $ 315,707 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 469,701 | $ 456,022 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 5.125% | 4.50% |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 6.50% | 6.50% |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 578,094 | $ 561,258 |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 722,618 | 701,572 |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | 433,571 | 420,943 |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 578,094 | 561,258 |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount | 384,342 | 381,105 |  |
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 480,427 | $ 476,381 |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 8.625% | 8.00% |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 10.00% | 10.00% |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 6.625% | 6.00% |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 8.00% | 8.00% |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent) | 4.00% | 4.00% |  |
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 5.00% | 5.00% |  |
International Bank of Commerce, Brownsville |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount | $ 158,533 | $ 154,141 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 25.61% | 26.26% |  |
Total Capital (to Risk Weighted Assets), Actual Amount | $ 163,937 | $ 159,913 |  |
Tier 1 Capital (to Risk Weighted Assets), Actual Amount | 158,533 | 154,141 |  |
Tier 1 Capital (to Average Assets), Actual Amount | $ 158,533 | $ 154,141 |  |
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 26.49% | 27.24% |  |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 25.61% | 26.26% |  |
Tier 1 capital (to Average Assets), Actual Ratio (as a percent) | 16.91% | 15.03% |  |
International Bank of Commerce, Brownsville | Minimum |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 27,852 | $ 26,418 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 40,230 | $ 38,159 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 5.125% | 4.50% |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 6.50% | 6.50% |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 49,514 | $ 46,965 |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 61,892 | 58,706 |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | 37,135 | 35,224 |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 49,514 | 46,965 |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount | 37,509 | 41,034 |  |
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 46,886 | $ 51,293 |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 8.625% | 8.00% |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 10.00% | 10.00% |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 6.625% | 6.00% |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 8.00% | 8.00% |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent) | 4.00% | 4.00% |  |
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 5.00% | 5.00% |  |
International Bank of Commerce, Zapata |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount | $ 65,989 | $ 66,153 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 34.09% | 35.71% |  |
Total Capital (to Risk Weighted Assets), Actual Amount | $ 67,464 | $ 67,470 |  |
Tier 1 Capital (to Risk Weighted Assets), Actual Amount | 65,989 | 66,153 |  |
Tier 1 Capital (to Average Assets), Actual Amount | $ 65,989 | $ 66,153 |  |
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 34.85% | 36.42% |  |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 34.09% | 35.71% |  |
Tier 1 capital (to Average Assets), Actual Ratio (as a percent) | 13.87% | 13.15% |  |
International Bank of Commerce, Zapata | Minimum |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 8,712 | $ 8,336 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 12,584 | $ 12,042 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 5.125% | 4.50% |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 6.50% | 6.50% |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 15,488 | $ 14,820 |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 19,360 | 18,525 |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | 11,616 | 11,115 |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 15,488 | 14,820 |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount | 19,029 | 20,129 |  |
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 23,786 | $ 25,161 |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 8.625% | 8.00% |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 10.00% | 10.00% |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 6.625% | 6.00% |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 8.00% | 8.00% |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent) | 4.00% | 4.00% |  |
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 5.00% | 5.00% |  |
Commerce Bank |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount | $ 73,765 | $ 72,882 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 31.84% | 36.17% |  |
Total Capital (to Risk Weighted Assets), Actual Amount | $ 76,093 | $ 74,204 |  |
Tier 1 Capital (to Risk Weighted Assets), Actual Amount | 73,765 | 72,882 |  |
Tier 1 Capital (to Average Assets), Actual Amount | $ 73,765 | $ 72,882 |  |
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 32.85% | 36.83% |  |
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent) | 31.84% | 36.17% |  |
Tier 1 capital (to Average Assets), Actual Ratio (as a percent) | 13.05% | 12.94% |  |
Commerce Bank | Minimum |  |  |  |
Capital Requirements |  |  |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 10,425 | $ 9,067 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 15,058 | $ 13,097 |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 5.125% | 4.50% |  |
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 6.50% | 6.50% |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | $ 18,532 | $ 16,119 |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 23,166 | 20,149 |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount | 13,899 | 12,089 |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | 18,532 | 16,119 |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount | 22,607 | 22,521 |  |
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount | $ 28,259 | $ 28,151 |  |
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 8.625% | 8.00% |  |
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 10.00% | 10.00% |  |
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent) | 6.625% | 6.00% |  |
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 8.00% | 8.00% |  |
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent) | 4.00% | 4.00% |  |
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent) | 5.00% | 5.00% |  |

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- Definition The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition Tier 1 Risk Based Capital as defined in the regulations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 + Details
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- Definition The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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- Definition The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958570-112826 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1H -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826 + Details
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- Definition The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826 + Details
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