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Regulatory Capital (Regulatory Capital Ratios) (Details) $ in Thousands | Mar. 31, 2021 USD ($) | Dec. 31, 2020 USD ($)
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Compliance with Regulatory Capital Requirements under Banking Regulations |  |
Total capital | $ 267,291 | $ 258,607
Total capital to risk-weighted assets | 0.1152 | 0.1125
Total capital, Minimum Required for Capital Adequacy Purposes | $ 185,682 | $ 183,965
Total capital to risk-weighted assets, Minimum Required for Capital Adequacy Purposes | 0.0800 | 0.0800
Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 243,708 | $ 241,454
Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 10.50% | 10.50%
Tier 1 capital | $ 214,510 | $ 206,104
Tier 1 capital to risk-weighted assets | 0.0924 | 0.0896
Tier 1 capital, Minimum Required for Capital Adequacy Purposes | $ 139,262 | $ 137,974
Tier 1 capital to risk-weighted assets, Minimum Required for Capital Adequacy Purposes | 0.0600 | 0.0600
Tier One Risk Based Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 197,288 | $ 195,463
Tier One Risk Based Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 8.50% | 8.50%
Common equity tier 1 capital | $ 204,445 | $ 196,042
Common equity tier 1 capital to risk-weighted assets | 8.81% | 8.53%
Common equity tier 1 capital, Minimum Required for Capital Adequacy Purposes | $ 104,446 | $ 103,480
Common equity tier 1 capital to risk-weighted assets, Minimum Required for Capital Adequacy Purposes | 4.50% | 4.50%
Common Equity Tier One Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 162,472 | $ 160,970
Common Equity Tier One Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 7.00% | 7.00%
Tier 1 leverage capital | $ 214,510 | $ 206,104
Tier 1 leverage capital to average assets | 0.0837 | 0.0799
Tier 1 leverage capital, Minimum Required for Capital Adequacy Purposes | $ 102,499 | $ 103,228
Tier 1 leverage capital to average assets, Minimum Required for Capital Adequacy Purposes | 0.0400 | 0.0400
Tier One Leverage Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 102,499 | $ 103,228
Tier One Leverage Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 4.00% | 4.00%
First Business Bank |  |
Compliance with Regulatory Capital Requirements under Banking Regulations |  |
Total capital | $ 260,529 | $ 251,116
Total capital to risk-weighted assets | 0.1124 | 0.1097
Total capital, Minimum Required for Capital Adequacy Purposes | $ 185,412 | $ 183,053
Total capital to risk-weighted assets, Minimum Required for Capital Adequacy Purposes | 0.0800 | 0.0800
Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 243,354 | $ 240,257
Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 10.50% | 10.50%
Total capital, Minimum Required to be Well Capitalized Under Prompt Corrective Action Requirements | $ 231,765 | $ 228,816
Total capital to risk-weighted assets, Minimum Required to be Well Capitalized Under Prompt Corrective Action Requirements | 0.1000 | 0.1000
Tier 1 capital | $ 231,547 | $ 222,500
Tier 1 capital to risk-weighted assets | 0.0999 | 0.0972
Tier 1 capital, Minimum Required for Capital Adequacy Purposes | $ 139,059 | $ 137,290
Tier 1 capital to risk-weighted assets, Minimum Required for Capital Adequacy Purposes | 0.0600 | 0.0600
Tier One Risk Based Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 197,001 | $ 194,494
Tier One Risk Based Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 8.50% | 8.50%
Tier 1 capital, Minimum Required to be Well Capitalized Under Prompt Corrective Action Requirements | $ 185,412 | $ 183,053
Tier 1 capital to risk weighted assets, Minimum Required to be Well Capitalized Under Prompt Corrective Action Requirements | 0.0800 | 0.0800
Common equity tier 1 capital | $ 231,547 | $ 222,500
Common equity tier 1 capital to risk-weighted assets | 9.99% | 9.72%
Common equity tier 1 capital, Minimum Required for Capital Adequacy Purposes | $ 104,294 | $ 102,967
Common equity tier 1 capital to risk-weighted assets, Minimum Required for Capital Adequacy Purposes | 4.50% | 4.50%
Common Equity Tier One Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 162,236 | $ 160,171
Common Equity Tier One Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 7.00% | 7.00%
Common equity tier 1 capital, Minimum Required to Be Well Capitalized Under Prompt Corrective Action Requirements | $ 150,648 | $ 148,731
Common equity tier 1 capital to risk-weighted assets, Minimum Required to Be Well Capitalized Under Prompt Corrective Action Requirements | 6.50% | 6.50%
Tier 1 leverage capital | $ 231,547 | $ 222,500
Tier 1 leverage capital to average assets | 0.0908 | 0.0867
Tier 1 leverage capital, Minimum Required for Capital Adequacy Purposes | $ 102,027 | $ 102,635
Tier 1 leverage capital to average assets, Minimum Required for Capital Adequacy Purposes | 0.0400 | 0.0400
Tier One Leverage Capital Required for Capital Adequacy Plus Capital Conservation Buffer | $ 102,027 | $ 102,635
Tier One Leverage Capital Required for Capital Adequacy Plus Conservation Buffer to Risk Weighted Assets | 4.00% | 4.00%
Tier 1 leverage capital, Minimum Required to be Well Capitalized Under Prompt Corrective Action Requirements | $ 127,534 | $ 128,294
Tier 1 leverage capital to average assets, Minimum Required to be Well Capitalized Under Prompt Corrective Action Requirements | 0.0500 | 0.0500

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