Fair Value - Summary of Assets and Liabilities in Each Level of Fair Value Hierarchy (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Residential loans at fair value	$ 10,725,232	$ 12,416,542
Receivables related to Non-Residual Trusts	5,608	15,033
Servicing rights carried at fair value	714,774	949,593	$ 1,682,016
Derivative instruments	29,394	87,937
Liabilities
Derivative instruments	1,250	11,804
Servicing rights related liabilities	32	1,902
Mortgage-backed debt related to Non-Residual Trusts	348,682	514,025
HMBS related obligations	9,175,128	10,509,449
Reverse Loans [Member]
Assets
Residential loans at fair value	9,789,444	10,742,922
Mortgage Loans Related To Non-Residual Trusts [Member]
Assets
Residential loans at fair value	301,435	450,377
Mortgage Loans Held For Sale [Member]
Assets
Residential loans at fair value	588,553	1,176,280
Charged-off Loans [Member]
Assets
Residential loans at fair value	45,800	46,963
Recurring Measurement Basis [Member] \| Level 2 [Member]
Assets
Servicing rights carried at fair value	0	13,170
Derivative instruments	2,757	34,543
Assets	591,242	1,223,993
Liabilities
Derivative instruments	981	7,611
Servicing rights related liabilities	32	1,902
Liabilities	1,013	9,513
Recurring Measurement Basis [Member] \| Level 2 [Member] \| Mortgage Loans Held For Sale [Member]
Assets
Residential loans at fair value	588,485	1,176,280
Recurring Measurement Basis [Member] \| Level 3 [Member]
Assets
Receivables related to Non-Residual Trusts	5,608	15,033
Servicing rights carried at fair value	714,774	936,423
Assets	10,883,766	12,245,112
Liabilities
Mortgage-backed debt related to Non-Residual Trusts	348,682	514,025
HMBS related obligations	9,175,128	10,509,449
Liabilities	9,524,079	11,027,667
Recurring Measurement Basis [Member] \| Level 3 [Member] \| Reverse Loans [Member]
Assets
Residential loans at fair value	9,789,444	10,742,922
Recurring Measurement Basis [Member] \| Level 3 [Member] \| Mortgage Loans Related To Non-Residual Trusts [Member]
Assets
Residential loans at fair value	301,435	450,377
Recurring Measurement Basis [Member] \| Level 3 [Member] \| Mortgage Loans Held For Sale [Member]
Assets
Residential loans at fair value	68	0
Recurring Measurement Basis [Member] \| Level 3 [Member] \| Charged-off Loans [Member]
Assets
Residential loans at fair value	45,800	46,963
Interest Rate Lock Commitments [Member]
Assets
Derivative instruments	26,637	53,394
Liabilities
Derivative instruments	269	4,193
Interest Rate Lock Commitments [Member] \| Recurring Measurement Basis [Member] \| Level 3 [Member]
Assets
Derivative instruments	26,637	53,394
Liabilities
Derivative instruments	$ 269	$ 4,193

Beneficial interest at fair value.

No definition available.

Name:	dhcp_BeneficialInterestAtFairValue
Namespace Prefix:	dhcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Liability related to the transfer of home equity conversion mortgage backed security related obligations, which is accounted for as a secured borrowing.

+ References

No definition available.

+ Details

Name:	dhcp_HomeEquityConversionMortgageBackedSecurityRelatedObligations
Namespace Prefix:	dhcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Liabilities incurred in connection with the Company's servicing assets, measured at fair value.

+ References

No definition available.

+ Details

Name:	dhcp_ServicingRightsRelatedLiabilitiesAtFairValue
Namespace Prefix:	dhcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(5))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13487-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(4))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(9))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_AccountsReceivableFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_AssetsFairValueDisclosureRecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

Name:	us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

+ Details

Name:	us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity.

+ References

No definition available.

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosureRecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

+ Details

Name:	us-gaap_LoansReceivableFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FairValueByAssetClassAxis=dhcp_ReverseLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=dhcp_ResidentialLoansRelatedToNonResidualTrustsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=dhcp_MortgageLoansHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=dhcp_ChargedOffLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_InterestRateLockCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: