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Including the current and noncurrent portions, the carrying value as of the balance sheet date of notes payable to banks, excluding mortgage notes, initially due beyond one year or beyond the operating cycle if longer.

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Cash from (used in) reorganization activities.

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Court's valuation.

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Elimination of net operating loss value.

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Net assets or equity value.

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Percentage of valuation allowance applicable to net operating loss.

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Fresh Start Accounting - Assets and Liabilities at Fair Value (Parenthetical) (Detail) (USD $)	0 Months Ended	3 Months Ended
	Mar. 19, 2012	Mar. 19, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fresh-Start Adjustment [Line Items]
Common stock, par value			$ 0.00001	$ 0.00001
Common stock, shares outstanding			202,343,245us-gaap_CommonStockSharesOutstanding	201,842,351us-gaap_CommonStockSharesOutstanding	201,156,078us-gaap_CommonStockSharesOutstanding
Common stock, shares issued			202,343,245us-gaap_CommonStockSharesIssued	201,842,351us-gaap_CommonStockSharesIssued
Common stock, shares authorized			500,000,000us-gaap_CommonStockSharesAuthorized	500,000,000us-gaap_CommonStockSharesAuthorized
Loss contract fair market value reserve	$ 63,100,000wmih_LossContractFairMarketValueReserve	$ 63,100,000wmih_LossContractFairMarketValueReserve	$ 12,549,000wmih_LossContractFairMarketValueReserve	$ 46,319,000wmih_LossContractFairMarketValueReserve
Reduction in WMMRC's FMV	8,400,000wmih_FairMarketValueReduction	8,400,000wmih_FairMarketValueReduction
Value related to NOLs	70,000,000wmih_EliminationOfNetOperatingLossValue	70,000,000wmih_EliminationOfNetOperatingLossValue
Valuation allowance	100.00%	100.00%
Runoff Notes [Member]
Fresh-Start Adjustment [Line Items]
Outstanding amount of notes	130,000,000	130,000,000
WMMRC [Member]
Fresh-Start Adjustment [Line Items]
Court's valuation of WMMRC	140,000,000	140,000,000
Net assets or equity value	171,600,000	171,600,000
Reduction in WMMRC's FMV	8,400,000	8,400,000
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares outstanding	200,000,000	200,000,000
Common stock, shares issued	200,000,000	200,000,000
Common stock, shares authorized	500,000,000	500,000,000
Fair Value Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Common stock, par value	$ 1	$ 1
Common stock, shares outstanding	1,000	1,000
Common stock, shares issued	1,000	1,000
Successor [Member]
Fresh-Start Adjustment [Line Items]
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares issued	200,000,000	200,000,000
Predecessor [Member]
Fresh-Start Adjustment [Line Items]
Increase in equity value	194,700,000
Cash contributed to the Company by creditors	$ 75,000,000	$ 75,000,000
Reorganization Adjustments [Member]
Fresh-Start Adjustment [Line Items]
Common stock, shares issued	200,000,000	200,000,000