Commitments and Contingencies - Additional Information (Detail)		3 Months Ended	12 Months Ended
	Apr. 15, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) Trust	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Loss Contingencies [Line Items]
Mandatory cleanup calls required when loan pool falls to percent of original principal balance		10.00%	10.00%
Percentage of maximum claim amount, repurchase threshold		98.00%	98.00%
Period from repurchase to liquidation for performing repurchased loans			30 days
Reverse loans and real estate owned repurchased from securitization pools			$ 671,400,000	$ 333,200,000
Repurchased reverse loans and real estate owned		$ 12,416,542,000	$ 12,416,542,000	12,673,439,000
Period loans were sold, basis for maximum exposure for repurchases			beginning of 2013 through December 31, 2016
Curtailment liability		121,305,000	$ 121,305,000	115,453,000
Leases expire through date			Nov. 30, 2026
Rent expense			$ 19,100,000	21,600,000	$ 26,700,000
Period Of Walter Energy Consolidated Group Tax Liability			2009 and prior tax years
Tax separation agreement date			Apr. 17, 2009
Period Of Walter Energy Proof Of Claim			August 31, 1983 through May 31, 1994
Walter Energy Federal Income Tax Years Under Audit			years ended May 31, 2000 through December 31, 2008
Walter Energy Additional Federal Income Tax Years under Audit			2009 through 2013 tax years
Walter Energy Tax Year Under Audit			2009
Beck V. Walter Investment Management Corp Et Al [Member]
Loss Contingencies [Line Items]
Total payment to fully resolve all claims	$ 24,000,000
Elimination of litigation reserve		24,000,000
Circeo-Loudon V Green Tree Servicing LLC Et Al [Member]
Loss Contingencies [Line Items]
Period Of Release From Certain Claims And Ability To Earn Commissions On Placement Of Lender-Placed Insurance			5 years
Commencement date of release			Jan. 27, 2017
Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency accrual		48,000,000	$ 48,000,000
Minimum [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Aggregate estimated amount of reasonably possible losses in excess of recorded liability		0	0
Maximum [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Aggregate estimated amount of reasonably possible losses in excess of recorded liability		15,000,000	15,000,000
Curtailment Obligation Liability [Member]
Loss Contingencies [Line Items]
Loss contingency recorded in current period			16,000,000
Civil Money Penalty [Member]
Loss Contingencies [Line Items]
Agreed to pay under CFPB settlement			325,000
Repurchased Reverse Loans And Real Estate Owned [Member]
Loss Contingencies [Line Items]
Repurchased reverse loans and real estate owned		419,500,000	419,500,000
Commitment to Repurchase Loans [Member] | Representations And Warranties [Member]
Loss Contingencies [Line Items]
Commitments		62,300,000,000	62,300,000,000
Reverse Mortgage [Member] | Curtailment Obligation Liability [Member]
Loss Contingencies [Line Items]
Curtailment liability		103,100,000	103,100,000
Aggregate estimated amount of reasonably possible losses in excess of recorded liability		142,600,000	142,600,000
Reverse Mortgage [Member] | Additional Borrowing Capacity Floating Rate Reverse Mortgage Loans [Member]
Loss Contingencies [Line Items]
Commitments		1,300,000,000	1,300,000,000
Borrowing capacity eligible to be drawn by borrowers at December 31, 2016		1,000,000,000	1,000,000,000
Borrowing capacity eligible to be drawn by borrowers through December 31, 2017		215,300,000	215,300,000
Reverse Mortgage [Member] | Commitment To Fund Protective Advances [Member]
Loss Contingencies [Line Items]
Commitments		26,000,000	26,000,000
Reverse Mortgage [Member] | Additional Borrowing Capacity Fixed Rate Reverse Mortgage Loans [Member]
Loss Contingencies [Line Items]
Commitments		500,000	500,000
Reverse Mortgage [Member] | Short Term Commitments To Lend [Member]
Loss Contingencies [Line Items]
Commitments		17,200,000	17,200,000
Reverse Mortgage [Member] | Loan Purchase Commitments [Member]
Loss Contingencies [Line Items]
Commitments to purchase loans		12,600,000	12,600,000
Reverse Mortgage [Member] | Loan Sale Commitments [Member]
Loss Contingencies [Line Items]
Commitments		32,000,000	32,000,000
Originations [Member] | Curtailment Obligation Liability [Member]
Loss Contingencies [Line Items]
Curtailment liability		18,200,000	18,200,000
Originations [Member] | Short Term Commitments To Lend [Member]
Loss Contingencies [Line Items]
Commitments		2,900,000,000	2,900,000,000
Originations [Member] | Commitment to Purchase Loans [Member]
Loss Contingencies [Line Items]
Commitments to purchase loans		97,800,000	97,800,000
Originations [Member] | Commitment to Purchase Loans [Member] | Representations And Warranties [Member]
Loss Contingencies [Line Items]
Loss contingency accrual		22,094,000	22,094,000	23,145,000	$ 10,959,000	$ 9,134,000
Originations [Member] | Commitment to Purchase Loans [Member] | Representations And Warranties [Member] | Warranty Obligations [Member]
Loss Contingencies [Line Items]
Decrease in liability associated with representations and warranties exposure			8,900,000
Originations [Member] | Commitment To Sell Securities [Member]
Loss Contingencies [Line Items]
Commitments		4,000,000,000	4,000,000,000
Originations [Member] | Commitment to Purchase Mortgage Backed Securities [Member]
Loss Contingencies [Line Items]
Commitments		600,000,000	$ 600,000,000
VIE [Member]
Loss Contingencies [Line Items]
Number of securitization trusts with reimbursement obligations | Trust			11
Reimbursement obligation on LOC, if drawn		165,000,000	$ 165,000,000
Amount available on LOCs for securitization trusts		254,100,000	254,100,000	260,400,000
Variable Interest Entity, Primary Beneficiary [Member]
Loss Contingencies [Line Items]
Repurchased reverse loans and real estate owned		492,499,000	492,499,000	526,016,000
Variable Interest Entity, Primary Beneficiary [Member] | Non-Residual Trusts [Member]
Loss Contingencies [Line Items]
Repurchased reverse loans and real estate owned		450,377,000	$ 450,377,000	$ 526,016,000
Variable Interest Entity, Primary Beneficiary [Member] | Non-Residual Trusts [Member] | Mandatory Clean-up Call For Residential Loans [Member]
Loss Contingencies [Line Items]
Expected period to exercise mandatory clean-up call obligation			2017 and continuing through 2019
Total outstanding balance of residential loans expected to be called		418,100,000	$ 418,100,000
Estimated call obligations in 2017		101,400,000	101,400,000
Estimated call obligations in 2018		253,500,000	253,500,000
Estimated call obligations in 2019		$ 63,200,000	$ 63,200,000