Payables and Accrued Liabilities - Schedule of Payables and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts Payable And Accrued Liabilities [Line Items]
Loans subject to repurchase from Ginnie Mae (1)	$ 184,289	$ 22,507
Accounts payable and accrued liabilities	155,556	113,325
Curtailment liability	121,305	115,453
Employee-related liabilities	91,063	95,926
Originations liability	62,969	48,930
Margin payable on derivative instruments	30,941	10,101
Servicing rights and related advance purchases payable	18,187	21,649
Derivative instruments	11,804	6,475
Uncertain tax positions (2)	9,414	64,554
Accrued interest payable	9,414	9,819
Payables to insurance carriers (3)	5,452	21,356
Acquisition related escrow funds payable to sellers	1,236	10,236
Other	57,381	57,595
Total payables and accrued liabilities	$ 759,011	597,926
Restatement Adjustment [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Error Correction, Decrease In Liabilities		42,100
Restatement Adjustment [Member] | Accounts Payable and Accrued Liabilities [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Error Correction, Decrease In Liabilities		$ 42,100