Variable Interest Entities - Summary of Assets and Liabilities of Consolidated VIEs (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Restricted cash and cash equivalents	$ 172,677	$ 204,463
Residential loans at amortized cost, net	709,080	665,209
Residential loans at fair value	11,905,869	12,416,542
Receivables, net	155,250	267,962
Servicer and protective advances, net	915,185	1,195,380
Other assets	199,554	242,290
Total assets	15,595,514	16,458,970
Liabilities
Payables and accrued liabilities	701,390	759,011
Servicing advance liabilities	544,134	783,229
Mortgage-backed debt	877,775	943,956
Total liabilities	15,708,495	16,483,410
VIE Primary Beneficiary
Assets
Restricted cash and cash equivalents	32,903	45,843
Residential loans at amortized cost, net	442,566	462,877
Residential loans at fair value	406,006	492,499
Receivables, net	12,112	15,798
Servicer and protective advances, net	493,595	734,707
Other assets	23,362	19,831
Total assets	1,410,544	1,771,555
Liabilities
Payables and accrued liabilities	2,565	2,985
Servicing advance liabilities	424,555	650,565
Mortgage-backed debt	877,775	943,956
Total liabilities	1,304,895	1,597,506
VIE Primary Beneficiary | Residual Trusts
Assets
Restricted cash and cash equivalents	12,861	13,321
Residential loans at amortized cost, net	442,566	462,877
Residential loans at fair value	0	0
Receivables, net	0	0
Servicer and protective advances, net	0	0
Other assets	9,652	10,028
Total assets	465,079	486,226
Liabilities
Payables and accrued liabilities	1,997	2,140
Servicing advance liabilities	0	0
Mortgage-backed debt	407,175	429,931
Total liabilities	409,172	432,071
VIE Primary Beneficiary | Non-Residual Trusts
Assets
Restricted cash and cash equivalents	10,714	10,257
Residential loans at amortized cost, net	0	0
Residential loans at fair value	406,006	450,377
Receivables, net	11,841	15,033
Servicer and protective advances, net	0	0
Other assets	653	1,028
Total assets	429,214	476,695
Liabilities
Payables and accrued liabilities	0	0
Servicing advance liabilities	0	0
Mortgage-backed debt	470,600	514,025
Total liabilities	470,600	514,025
VIE Primary Beneficiary | Servicer and Protective Advance Financing Facilities
Assets
Restricted cash and cash equivalents	9,328	22,265
Residential loans at amortized cost, net	0	0
Residential loans at fair value	0	0
Receivables, net	0	0
Servicer and protective advances, net	493,595	734,707
Other assets	618	1,440
Total assets	503,541	758,412
Liabilities
Payables and accrued liabilities	568	845
Servicing advance liabilities	424,555	650,565
Mortgage-backed debt	0	0
Total liabilities	425,123	651,410
VIE Primary Beneficiary | Revolving Credit Facilities Related VIEs
Assets
Restricted cash and cash equivalents	0	0
Residential loans at amortized cost, net	0	0
Residential loans at fair value	0	42,122
Receivables, net	271	765
Servicer and protective advances, net	0	0
Other assets	12,439	7,335
Total assets	12,710	50,222
Liabilities
Payables and accrued liabilities	0	0
Servicing advance liabilities	0	0
Mortgage-backed debt	0	0
Total liabilities	$ 0	$ 0