Servicing of Residential Loans - Schedule of Net Servicing Revenue and Fees (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fees Earned in Exchange for Servicing Financial Assets [Line Items]
Servicing fees	$ 129,154	$ 177,082	$ 262,547	$ 354,836
Incentive and performance fees	16,795	18,011	31,949	37,783
Ancillary and other fees	22,012	25,058	45,255	49,667
Servicing revenue and fees	167,961	220,151	339,751	442,286
Amortization of servicing rights	(9,926)	(2,625)	(14,951)	(7,236)
Change in fair value of servicing rights	(66,714)	(187,493)	(120,230)	(514,073)
Change in fair value of servicing rights related liabilities	0	1,903	(62)	5,197
Net servicing revenue and fees	91,321	31,936	204,508	(73,826)
Late fees	14,900	17,900	30,500	33,700
Amortization of a servicing liability	1,300	3,100	2,100	4,300
Impairment of servicing rights and a servicing liability	8,000		11,100
Interest expense	$ 60,884	64,400	$ 121,294	128,648
Servicing Rights Related Liabilities
Fees Earned in Exchange for Servicing Financial Assets [Line Items]
Interest expense		3,100		7,000
Corporate Joint Venture | Sub-servicing Performed For WCO
Fees Earned in Exchange for Servicing Financial Assets [Line Items]
Sub-servicing fees related to servicing assets held by WCO		1,200		2,100
Incentive, performance, ancillary and other fees related to servicing assets held by WCO		100		300
Corporate Joint Venture | Sale Of Servicing Rights To WCO
Fees Earned in Exchange for Servicing Financial Assets [Line Items]
Servicing fees		$ 1,800		$ 3,000