XML 73 R63.htm IDEA: XBRL DOCUMENT
v3.21.2

GUARANTEES AND MORTGAGE REPURCHASE LIABILITY - Narrative (Details) - USD ($) | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Jun. 30, 2021 | Dec. 31, 2020 | Jun. 30, 2020 | Dec. 31, 2019
Representations and warranties reserve for loan receivables |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |
Unfunded commitment balance of loans sold on a servicing-retained basis | $ 5,600,000,000 |  | $ 5,600,000,000 |  |  | $ 6,000,000,000 |  |
Reserve liability related to mortgage repurchase | 1,443,000 | $ 2,095,000 | 1,443,000 | $ 2,095,000 | $ 1,612,000 | 2,122,000 | $ 2,083,000 | $ 2,871,000
Loss sharing relationship |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |
Reserve liability related to multifamily DUS program | 700,000 |  | 700,000 |  |  | 2,100,000 |  |
Loss sharing relationship | Multifamily |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |
UPB of loans sold through DUS | 1,900,000,000 |  | 1,900,000,000 |  |  | 1,800,000,000 |  |
Losses incurred - related to DUS | 0 | $ 0 | 0 | $ 0 |  |  |  |
Credit risk |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |
Reserve liability related to mortgage repurchase | $ 1,400,000 |  | $ 1,400,000 |  |  | $ 2,100,000 |  |

X
- Definition Unpaid principal of Loans sold through DUS program. + References No definition available. + Details
Name: | hmst_LoanssoldthroughDUS
Namespace Prefix: | hmst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Reserve liability related to multifamily DUS Program + References No definition available. + Details
Name: | hmst_ReserveliabilityrelatedtomultifamilyDUSProgram
Namespace Prefix: | hmst_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loss contingency liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349 + Details
Name: | us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349 + Details
Name: | us-gaap_LossContingencyLossInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=hmst_RepresentationsAndWarrantiesReserveForLoanReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=hmst_LossSharingRelationshipMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=hmst_MultifamilyResidentialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_CreditRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |