Capital Stock - Additional Information (Detail) (USD $)	0 Months Ended	9 Months Ended		12 Months Ended							9 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended
	Jan. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Mar. 19, 2012	Sep. 30, 2014 Restricted shares subject to repurchase [Member]	Dec. 31, 2013 Restricted shares subject to repurchase [Member]	Dec. 31, 2012 Restricted shares subject to repurchase [Member]	Sep. 30, 2014 Warrant One [Member]	Sep. 30, 2014 Warrant Two [Member]	Sep. 30, 2014 Series A Convertible Preferred Stock [Member]	Jan. 30, 2014 Convertible Preferred Stock [Member]	Jan. 30, 2014 Convertible Preferred Stock [Member]	Jan. 30, 2014 Convertible Preferred Stock [Member] Maximum [Member]	Mar. 19, 2012 Reorganization Adjustments [Member]
Capital Stock Distribution [Line Items]
Common stock, shares authorized		500,000,000		500,000,000
Preferred stock, shares authorized		5,000,000		5,000,000
Preferred stock, par value		$ 0.00001		$ 0.00001
Common stock, par value		$ 0.00001		$ 0.00001
Common stock, shares issued		202,343,245		201,842,351											200,000,000
Convertible preferred stock, shares issued		1,000,000		0							1,000,000
Purchase price of convertible preferred stock maximum limit											$ 11,100,000
Warrants to purchase in aggregate, shares		61,400,000
Warrants to purchase common stock									30,700,000	30,700,000
Warrants to purchase common stock, exercise price									$ 1.32	$ 1.43
Preferred stock liquidation preference											The Convertible Preferred Stock has rights substantially similar to those associated with WMIHC’s common stock, with the exception of a liquidation preference, conversion rights and customary anti-dilution protections. The Convertible Preferred Stock has a liquidation preference equal to the greater of (i) $10.00 per one million shares of Convertible 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 Convertible Preferred Stock been converted to common stock of WMIHC.
Convertible preferred stock conversion price		$ 1.10
Preferred stock liquidation preference per share		$ 10.00
Convertible Preferred Stock, shares		1,000,000
Preferred deemed dividend		(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%
Percentage of rights vest with preferred shareholders to future offering														50.00%
Expiration of right to participating into future offering												Jan. 30, 2017
Preferred stock participation value														1,000,000,000
Preferred stock participation right													Additionally, until January 30, 2017, the Holders will have the right to purchase up to 50% of any future equity rights offerings or other equity issuance by WMIHC on the same terms as the equity issued to other investors in such transactions, in an aggregate amount of such offerings and issuances by WMIHC of up to $1.0 billion
Registration right period	180 days
Amount of restricted share grants		600,000
Amount of additional restricted share grants issued		700,000		700,000
Award vesting period		3 years
Unamortized value of unvested restricted share grant		1,439,000		700,000
Equity-based compensation		$ 600,000	$ 301,000	$ 401,000
Unvested shares						1,343,764	1,456,987	1,156,078
Per share of unvested shares of common stock		$ 0.0001
Common stock, shares outstanding		202,343,245		201,842,351
Preferred stock, shares outstanding		1,000,000		0
Warrants to purchase common stock, outstanding		61,400,000		0