Service Agreements and Related Party Transactions - Additional Information (Detail) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Feb. 02, 2015 USD ($)	Oct. 14, 2014 Directors	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jan. 05, 2015 USD ($)
Related Party Transaction [Line Items]
Payment of stock offering fee				$ 19,310	$ 3,348
WMMRC [Member]
Related Party Transaction [Line Items]
Administrative services agreement fee				$ 110
Pro Rata Share of the Common Stock Allotment | shares				10,000,000
Percentage of Pro Rata Share of the Common Stock Election				5.00%
Percentage of interest in litigation proceeds				50.00%
Lawsuit against number of former directors | Directors		16
Litigation settlement amount				$ 37,000
Proceeds from litigation settlement amount	$ 9,000
Litigation settlement reserve for reimbursement of contingent fees and expenses							$ 3,000
WMMRC [Member] | Runoff Notes [Member]
Related Party Transaction [Line Items]
Principal amount of Runoff Notes | $ / shares				$ 1.00
WMMRC [Member] | Investment Management Agreement And Administrative Services Agreement [Member]
Related Party Transaction [Line Items]
Expenses incurred under the agreements				$ 1,400	$ 1,500	$ 1,700
WMMRC [Member] | Investment Management Agreement [Member]
Related Party Transaction [Line Items]
Description of fee				fee equal to the product of (x) the ending dollar amount of assets under management during the calendar month in question and (y) .002 divided by 12.
WMI Holdings Corp [Member]
Related Party Transaction [Line Items]
Litigation settlement amount				$ 100
Proceeds from litigation settlement amount			$ 8,300
Litigation settlement reserve for reimbursement of contingent fees and expenses				500
Net proceeds from litigation settlement				34,000
Legal fees and expenses associated with the recovery of the litigation proceeds				600
Other income				7,800
KKR Capital Markets LLC [Member] | Redeemable Convertible Series B Preferred Stock [Member]
Related Party Transaction [Line Items]
Payment of stock offering fee				8,250
Payment of additional deferred Fee				$ 8,250