Regulatory Capital - Summary of Bank's Capital Ratios and Ratios Required by Federal Regulators (Detail)	Dec. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 ratio, Actual Ratio	18.66%
Common Equity Tier 1 ratio, Minimum Required Ratio	4.50%
Tier 1 capital ratio, Actual Ratio	18.66%
Tier 1 capital ratio, Minimum Required Ratio	6.00%
Total capital ratio, Actual Ratio	19.95%
Total capital ratio, Minimum Required Ratio	8.00%
Tier 1 leverage ratio, Actual Ratio	13.52%
Tier 1 leverage ratio, Minimum Required Ratio	4.00%
AnchorBank, fsb
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 ratio, Actual Ratio	17.04%
Common Equity Tier 1 ratio, Minimum Required Ratio	4.50%
Common equity tier 1 ratio, To be Well Capitalized	6.50%
Tier 1 capital ratio, Actual Ratio	17.04%	16.97%
Tier 1 capital ratio, Minimum Required Ratio	6.00%	4.00%
Tier 1 capital ratio, To be Well Capitalized	8.00%	6.00%
Total capital ratio, Actual Ratio	18.33%	18.25%
Total capital ratio, Minimum Required Ratio	8.00%	8.00%
Total capital ratio, To be Well Capitalized	10.00%	10.00%
Tier 1 leverage ratio, Actual Ratio	12.35%	10.43%
Tier 1 leverage ratio, Minimum Required Ratio	4.00%	4.00%
Tier 1 leverage ratio, To be Well Capitalized	5.00%	5.00%

Common Equity Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets

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Common Equity Tier One Risk Based Capital To Be Well Capitalized

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Common Equity Tier One Risk Based Capital To Risk Weighted Assets

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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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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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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.

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