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Regulatory Capital - Schedule of Actual Capital Amounts and Ratios and Selected Minimum Regulatory Thresholds (Details) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Total risk-based capital: |  |
Actual Amount | $ 1,310.3 | $ 1,285.0
Actual Ratio | 13.23% | 12.99%
Capital Required for Capital Adequacy under Basel III Fully Phased-in | $ 1,040.0 | $ 976.6
Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets | 10.50% | 9.875%
Well Capitalized Amount | $ 990.5 | $ 989.0
Well Capitalized Ratio | 10.00% | 10.00%
Tier 1 risk-based capital: |  |
Actual Amount | $ 1,237.9 | $ 1,212.0
Actual Ratio | 12.50% | 12.26%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in | $ 841.9 | $ 778.8
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets | 8.50% | 7.875%
Well Capitalized Amount | $ 792.4 | $ 791.2
Well Capitalized Ratio | 8.00% | 8.00%
Common equity tier one risk-based capital: |  |
Actual Amount | $ 1,153.7 | $ 1,127.8
Actual Ratio | 11.65% | 11.40%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule | $ 445.7 | $ 445.0
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets | 4.50% | 4.50%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in | $ 693.4 | $ 630.5
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets | 7.00% | 6.375%
Well Capitalized Amount | $ 643.8 | $ 642.8
Well Capitalized Ratio | 6.50% | 6.50%
Leverage capital ratio: |  |
Actual Amount | $ 1,237.9 | $ 1,212.0
Actual Ratio | 9.76% | 9.47%
Adequately Capitalized Amount | $ 507.5 | $ 511.9
Adequately Capitalized Ratio | 4.00% | 4.00%
Well Capitalized Amount | $ 634.4 | $ 639.9
Well Capitalized Ratio | 5.00% | 5.00%
Capital Required for Capital Adequacy | $ 792.4 | $ 791.2
Capital Required for Capital Adequacy to Risk Weighted Assets | 8.00% | 8.00%
Tier One Risk Based Capital Required for Capital Adequacy | $ 594.3 | $ 593.4
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets | 6.00% | 6.00%
FIB |  |
Total risk-based capital: |  |
Actual Amount | $ 1,201.4 | $ 1,184.5
Actual Ratio | 12.16% | 12.01%
Capital Required for Capital Adequacy under Basel III Fully Phased-in | $ 1,037.1 | $ 973.7
Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets | 10.50% | 9.875%
Well Capitalized Amount | $ 987.8 | $ 986.0
Well Capitalized Ratio | 10.00% | 10.00%
Tier 1 risk-based capital: |  |
Actual Amount | $ 1,129.0 | $ 1,111.6
Actual Ratio | 11.43% | 11.27%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in | $ 839.6 | $ 776.5
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets | 8.50% | 7.875%
Well Capitalized Amount | $ 790.2 | $ 788.8
Well Capitalized Ratio | 8.00% | 8.00%
Common equity tier one risk-based capital: |  |
Actual Amount | $ 1,129.0 | $ 1,111.6
Actual Ratio | 11.43% | 11.27%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule | $ 444.5 | $ 443.7
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets | 4.50% | 4.50%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in | $ 691.4 | $ 628.6
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets | 7.00% | 6.375%
Well Capitalized Amount | $ 642.0 | $ 640.9
Well Capitalized Ratio | 6.50% | 6.50%
Leverage capital ratio: |  |
Actual Amount | $ 1,129.0 | $ 1,111.6
Actual Ratio | 8.92% | 8.97%
Adequately Capitalized Amount | $ 506.3 | $ 495.9
Adequately Capitalized Ratio | 4.00% | 4.00%
Well Capitalized Amount | $ 632.8 | $ 619.8
Well Capitalized Ratio | 5.00% | 5.00%
Capital Required for Capital Adequacy | $ 790.2 | $ 788.8
Capital Required for Capital Adequacy to Risk Weighted Assets | 8.00% | 8.00%
Tier One Risk Based Capital Required for Capital Adequacy | $ 592.7 | $ 591.6
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets | 6.00% | 6.00%

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