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Capital Ratios (Details)	Jan. 01, 2016	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jul. 31, 2013
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)		19.51%	19.51%
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	0.625%			2.50%
CET 1 ratio		17.16%	17.11%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)		14.68%	14.62%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)		18.74%	18.73%		6.00%
Term of mandatory compliance	4 years
Minimum
CET 1 ratio		7.00%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)				4.50%	4.00%

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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