Deferred tax and current tax assets, tax credit carryforwards, alternative minimum tax.

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Income taxes.

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Operating loss carry forward expiration year.

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Tax credit carryforwards reclassified to current tax assets.

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Amount of bad debt reserves for tax purposes of qualified lenders excluded in calculating deferred taxes.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic operating loss carryforwards. Excludes state and local operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards.

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Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible alternative minimum tax credit carryforwards.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability not recognized because of the exceptions to comprehensive recognition of deferred taxes related to bad debt reserve for tax purposes of a qualified lender.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of income tax expense (benefit) from continuing operations attributable to an adjustment of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity.

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Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Taxes [Line Items]
Statutory rate	21.00%	35.00%	21.00%	35.00%
Estimated expense for revaluation of deferred tax assets					$ 39,300,000
Unrecognized tax benefits, if recognized, would favorably affect the effective tax rate	$ 500,000		$ 500,000
Decrease in unrecognized tax benefits			300,000
Bad debt reserves, created for tax purposes	52,800,000		52,800,000
Unrecognized deferred income tax liability	13,000,000.0		13,000,000.0
Valuation allowance recorded	0		0		0
Operating loss carryforwards, federal	104,500,000		104,500,000		130,700,000
AMT credit carryforwards	24,000,000.0		24,000,000.0		25,100,000
AMT carryforwards	2,545,000		2,545,000		25,084,000
Federal tax credits	12,142,000		12,142,000		5,516,000
Operating loss carryforwards, state	171,200,000		171,200,000		$ 203,600,000
Internal Revenue Code Section Three Eight Two [Member]
Income Taxes [Line Items]
Tax credit carryforwards reclassified to current tax asset			21,500,000
AMT carryforwards	2,500,000		$ 2,500,000
Minimum [Member] \| Federal Net Operating Loss [Member]
Income Taxes [Line Items]
Operating loss carryforwards, expiration date			2028
Minimum [Member] \| Federal Tax Credits [Member]
Income Taxes [Line Items]
Operating loss carryforwards, expiration date			2025
Minimum [Member] \| State Net Operating Loss [Member]
Income Taxes [Line Items]
Operating loss carryforwards, expiration date			2024
Maximum [Member] \| Federal Net Operating Loss [Member]
Income Taxes [Line Items]
Operating loss carryforwards, expiration date			2033
Maximum [Member] \| Federal Tax Credits [Member]
Income Taxes [Line Items]
Operating loss carryforwards, expiration date			2038
Maximum [Member] \| State Net Operating Loss [Member]
Income Taxes [Line Items]
Operating loss carryforwards, expiration date			2033
AnchorBank WI [Member]
Income Taxes [Line Items]
Bad debt reserves, created for tax purposes	50,900,000		$ 50,900,000
Lafayette Savings Bank [Member]
Income Taxes [Line Items]
Bad debt reserves, created for tax purposes	$ 1,900,000		$ 1,900,000