Capital Stock - Additional Information (Detail) - USD ($)				1 Months Ended	3 Months Ended			6 Months Ended			12 Months Ended
	May. 15, 2015	Apr. 28, 2015	Jan. 05, 2015	Jan. 30, 2015	Mar. 31, 2015	Mar. 31, 2014	Mar. 19, 2012	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	May. 11, 2015	May. 10, 2015	Jan. 30, 2014	Dec. 31, 2013
Capital Stock Distribution [Line Items]
Common stock, shares authorized								3,500,000,000	3,500,000,000		3,500,000,000	3,500,000,000	500,000,000
Preferred stock, shares authorized								10,000,000	10,000,000			10,000,000	5,000,000
Common stock, par value								$ 0.00001	$ 0.00001		$ 0.00001	$ 0.00001	$ 0.00001
Preferred stock, par value								0.00001	0.00001			$ 0.00001	$ 0.00001
Conversion of shares												1
Warrants to purchase in aggregate, shares														61,400,000
Convertible preferred stock conversion price									1.10
Preferred stock liquidation preference per share								$ 10.00	$ 10.00
Preferred deemed dividend						$ 9,455,000				$ 9,455,000
Warrants expiration period									5 years
Maximum percent of the voting shares of the emerging entity immediately prior to the confirmation of reorganization				42.50%			50.00%	50.00%	50.00%
Registration right period									180 days
Preferred stock dividend rate									3.00%
Escrow deposit			$ 598,500,000
Amount of restricted stock grants		$ 269,234							$ 3,555,556		$ 600,000
Amount of additional restricted stock grants issued		$ 700,000									700,000
Award vesting period									3 years
Unamortized value of unvested restricted share grant								$ 10,420,000	$ 10,420,000		$ 1,200,000
Share price	$ 2.76	$ 2.60
Equity-based compensation									$ 779,000	$ 373,000
Per share of unvested shares of common stock									$ 0.0001
Vested number of shares					190,070
Vested number of shares, outstanding					113,146
Expected increase in additional paid in capital due to early vesting of equity shares									$ 382,000
Expected increase in share based compensation due to early vesting of equity shares									$ 382,000
Vested number of shares, issued		76,924
Common stock, shares outstanding								206,168,035	206,168,035		202,343,245
Warrants to purchase common stock, outstanding								61,400,000	61,400,000		61,400,000
Chief Executive Officer [Member]
Capital Stock Distribution [Line Items]
Amount of restricted stock grants	$ 1,777,778
Chief Operating Officer [Member]
Capital Stock Distribution [Line Items]
Amount of restricted stock grants	1,777,778
EXEC Grants [Member]
Capital Stock Distribution [Line Items]
Amount of restricted stock grants	$ 9,800,000
Share price	$ 2.76
Restricted stock fair value									$ 9,300,000
Restricted stock price per share									$ 2.61
Restricted shares subject to repurchase [Member]
Capital Stock Distribution [Line Items]
Unvested shares								4,197,396	4,197,396		1,343,764				1,456,987
Convertible Series A [Member]
Capital Stock Distribution [Line Items]
Preferred stock, par value								$ 0.00001	$ 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														$ 11,100,000
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.
Preferred stock, shares outstanding								1,000,000	1,000,000		1,000,000
Convertible Preferred Stock [Member]
Capital Stock Distribution [Line Items]
Expiration of right to participating into future offering				Jan. 30, 2017
Preferred stock participation right									Additionally, until January 30, 2017, the Series A Holders will have the right to purchase up to 50% of any future equity rights offerings or other equity issuance by WMIH on the same terms as the equity issued to other investors in such transactions, in an aggregate amount of such offerings and issuances by WMIH of up to $1.0 billion
Convertible Preferred Stock [Member] | Maximum [Member]
Capital Stock Distribution [Line Items]
Maximum percent of the voting shares of the emerging entity immediately prior to the confirmation of reorganization				50.00%
Percentage of rights vest with preferred shareholders to future offering				50.00%
Preferred stock participation value				$ 1,000,000,000
Series B Preferred Stock [Member]
Capital Stock Distribution [Line Items]
Common stock, par value								$ 1.75	$ 1.75
Preferred stock, par value			$ 0.00001
Preferred stock, shares issued			600,000					600,000	600,000		0
Preferred stock liquidation preference per share			$ 1,000
Preferred stock dividend rate			3.00%
Number of trading periods									20 days
Aggregate fair value			$ 66,200,000					$ 141,400,000	$ 141,400,000
Changes in Fair Value								$ 75,200,000
Preferred stock, shares outstanding								600,000	600,000		0
Series B Preferred Stock [Member] | Maximum [Member]
Capital Stock Distribution [Line Items]
Common stock, par value								$ 2.25	$ 2.25
Series B Convertible Preferred Stock [Member]
Capital Stock Distribution [Line Items]
Share price	$ 2.25
Preferred stock, shares outstanding								600,000	600,000		0
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