Capital Stock and Derivative Instruments - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands					1 Months Ended	12 Months Ended
	Jun. 01, 2017	Jun. 01, 2016	Jan. 05, 2015	Mar. 19, 2012	Jan. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 05, 2018	Dec. 07, 2017	May 15, 2015	May 11, 2015	Dec. 31, 2014	Jan. 30, 2014
Capital Stock Distribution [Line Items]
Common stock, shares authorized				500,000,000		3,500,000,000	3,500,000,000					3,500,000,000
Preferred stock, shares authorized				5,000,000		10,000,000						10,000,000
Common stock, par value				$ 0.00001		$ 0.00001	$ 0.00001					$ 0.00001
Preferred stock, par value				$ 0.00001		$ 0.00001						$ 0.00001
Conversion of shares												1
Warrants to purchase in aggregate, shares														61,400,000
Warrants expiration period						5 years
Registration right period						180 days
Escrow deposit			$ 598,500			$ 578,900	$ 572,900
Acquisition meaning						. “Acquisition” means any acquisition by the Company (or any of its direct or indirect wholly-owned subsidiaries), in a single transaction or a series of transactions, whether by purchase, merger or otherwise, of all or substantially all of the assets of, or of 80% or more of the equity interests in, or a business line, unit or division of, any person.
Derivative asset - embedded conversion feature							80,651
Fair market value of embedded conversion feature, reclassed to equity						$ 108,900
Changes in fair value						28,242	201,499	$ (54,621)
Change in fair market value less reclass to equity						28,200
Reduction in other liabilities						$ (3,740)	294	(904)
Award vesting period						3 years
Number of additional Restricted Stock Awards Outstanding, Restricted stock awards granted						1,015,872
Unamortized value of unvested restricted share grant						$ 3,538	7,700	10,000
Equity-based compensation						$ 517	$ 658	$ 1,129
Per share of unvested shares of common stock						$ 0.0001
Common stock, shares issued						206,714,132	206,380,800	206,168,035
Common stock, shares outstanding						206,714,132	206,380,800	206,168,035
Warrants to purchase common stock, Issued						61,400,000	61,400,000	61,400,000
Warrants to purchase common stock, outstanding						61,400,000	61,400,000	61,400,000
Exec Grants [Member]
Capital Stock Distribution [Line Items]
Share price											$ 2.76
Restricted stock fair value						$ 3,900
Restricted stock price per share						$ 0.85
Chief Executive Officer [Member]
Capital Stock Distribution [Line Items]
Number of additional Restricted Stock Awards Outstanding, Restricted stock awards granted						507,936
Restricted stock award [Member]
Capital Stock Distribution [Line Items]
Amount of restricted stock grants	$ 400	$ 500				$ 400	$ 500	$ 700
Share price	$ 1.20	$ 2.35
Unvested shares						6,714,132	6,380,800	6,168,035					2,343,245
Number of Restricted Stock Awards Outstanding, Restricted stock awards granted	333,332	212,765				333,332	212,765	3,824,790
Restricted stock award [Member] | Exec Grants [Member]
Capital Stock Distribution [Line Items]
Amount of restricted stock grants											$ 9,800
Restricted shares subject to repurchase [Member]
Capital Stock Distribution [Line Items]
Unvested shares						4,053,640	4,039,591	4,197,396					1,343,764
Number of Restricted Stock Awards Outstanding, Restricted stock awards granted						333,332	212,765	3,824,790
Subsequent Event [Member]
Capital Stock Distribution [Line Items]
Conversion price of common stock									$ 1.35
Minimum [Member]
Capital Stock Distribution [Line Items]
Preferred stock liquidation preference per share						$ 10.00
Minimum [Member] | Exec Grants [Member]
Capital Stock Distribution [Line Items]
Preferred stock additional shares conversion price						1.75
Restricted stock price per share						1.75
Maximum [Member] | Exec Grants [Member]
Capital Stock Distribution [Line Items]
Preferred stock additional shares conversion price						2.25
Convertible Series A Preferred Stock [Member]
Capital Stock Distribution [Line Items]
Preferred stock, par value						$ 0.00001	$ 0.00001
Preferred stock, shares issued						1,000,000	1,000,000	1,000,000						1,000,000
Purchase price of convertible preferred stock maximum limit														$ 11,100
Preferred stock liquidation preference						The Series A Preferred Stock has rights substantially similar to those associated with WMIH’s common stock, with the exception of a liquidation preference, conversion rights and customary anti-dilution protections. The Series A Preferred Stock has a liquidation preference equal to the greater of (i) $10.00 per one million shares of Series A Preferred Stock plus declared but unpaid dividends on such shares and (ii) the amount that the holder would be entitled to in a relevant transaction had the Series A Preferred Stock been converted to common stock of WMIH.
Convertible preferred stock conversion price						$ 1.10
Preferred deemed dividend						$ 9,500
Preferred stock, shares outstanding						1,000,000	1,000,000	1,000,000
Redeemable Convertible Series B Preferred Stock [Member]
Capital Stock Distribution [Line Items]
Issuance of common stock, Shares								600,000
Preferred stock liquidation preference						If the Series B Preferred Stock is redeemed or determined likely to be redeemed, the Company would be required to record a charge to earnings of approximately $96.3 million to accrete the value of the Series B Preferred Stock to the $600.0 million redemption value. The Company continues to pursue its business strategy of consummating an acquisition, and to explore potential financing and refinancing alternatives, and as of December 31, 2017, the Company has determined that recording for accretion to the Series B Preferred Stock’s redemption value is not required.
Amendment effective term						18 months
Amendment Effective Date						Jan. 05, 2018
Minimum percentage of preferred stock beneficially to be owned by KRR funds and its affiliates for acquisition consent						50.00%
Preferred stock, shares issued			600,000			600,000	600,000	600,000
Preferred stock dividend rate calculated on interest rate			3.00%
Preferred stock, redemption date						Oct. 05, 2019
Payments to acquire businesses						$ 450,000
Preferred stock, shares outstanding						600,000	600,000	600,000
Preferred stock, redemption amount						$ 600,000
Preferred stock, accretion to redemption value						$ 96,300
Amendment Date						Dec. 08, 2017
Number of trading periods						20 days
Conversion ceiling price of common stock						$ 2.25				$ 2.25
Conversion floor price of common stock						$ 1.75				1.75
Derivative liability - embedded conversion feature			$ 66,200
Derivative asset - embedded conversion feature							$ 80,700
Fair market value of embedded conversion feature, reclassed to equity						$ 108,900
Changes in fair value						(80,700)	$ 201,500	$ 54,600
Change in fair market value less reclass to equity						28,200
Contingent fee, waived						4,000
Exchange fee for escrow agreement extension						2,500
Increase in mezzanine liability						1,500
Reduction in other liabilities						$ 1,500
Share price											$ 2.25
Redeemable Convertible Series B Preferred Stock [Member] | Subsequent Event [Member]
Capital Stock Distribution [Line Items]
Conversion price of common stock									$ 1.35
Payment of exchange fee for escrow agreement extension					$ 2,500
Redeemable Convertible Series B Preferred Stock [Member] | Derivative Asset [Member]
Capital Stock Distribution [Line Items]
Conversion floor price of common stock										1.75
Redeemable Convertible Series B Preferred Stock [Member] | Derivative Liability [Member]
Capital Stock Distribution [Line Items]
Conversion ceiling price of common stock										$ 2.25
Redeemable Convertible Series B Preferred Stock [Member] | Maximum [Member]
Capital Stock Distribution [Line Items]
Conversion ceiling price of common stock						$ 2.25
Common Stock [Member]
Capital Stock Distribution [Line Items]
Issuance of common stock, Shares				200,000,000
Warrant One [Member]
Capital Stock Distribution [Line Items]
Warrants to purchase common stock														30,700,000
Warrants to purchase common stock, exercise price														$ 1.32
Warrant Two [Member]
Capital Stock Distribution [Line Items]
Warrants to purchase common stock														30,700,000
Warrants to purchase common stock, exercise price														$ 1.43