XML 108 R95.htm IDEA: XBRL DOCUMENT
v3.20.4

Fair Value Measurements (Details 6) - Non-recurring $ in Thousands | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($)
--- | --- | ---
Level 3 |  |
Valuation Methodology |  |
Assets measured at fair value | $ 18,130 | $ 21,837
Carrying Value | Level 3 | Collateral based measurements | Collateral-dependent impaired loans |  |
Valuation Methodology |  |
Assets measured at fair value | 11,991 | 8,492
Carrying Value | Level 3 | Discounted cash flows | Mortgage servicing rights |  |
Valuation Methodology |  |
Assets measured at fair value | 3,804 | 4,200
Carrying Value | Level 3 | Appraisals trade publications and auction values | Repossessions |  |
Valuation Methodology |  |
Assets measured at fair value | 1,976 | 8,623
Carrying Value | Level 3 | Appraisals | Other real estate |  |
Valuation Methodology |  |
Assets measured at fair value | 359 | 522
Fair Value |  |
Valuation Methodology |  |
Assets measured at fair value | 18,130 | 21,837
Fair Value | Level 3 | Collateral based measurements | Collateral-dependent impaired loans |  |
Valuation Methodology |  |
Assets measured at fair value | 11,991 | 8,492
Fair Value | Level 3 | Discounted cash flows | Mortgage servicing rights |  |
Valuation Methodology |  |
Assets measured at fair value | 4,038 | 5,986
Fair Value | Level 3 | Appraisals trade publications and auction values | Repossessions |  |
Valuation Methodology |  |
Assets measured at fair value | 2,144 | 9,211
Fair Value | Level 3 | Appraisals | Other real estate |  |
Valuation Methodology |  |
Assets measured at fair value | $ 388 | $ 564
Discount for lack of marketability and current conditions | Level 3 | Collateral based measurements | Collateral-dependent impaired loans | Minimum |  |
Unobservable Inputs |  |
Impaired loans unobservable inputs (as a percent) | 0 | 0
Discount for lack of marketability and current conditions | Level 3 | Collateral based measurements | Collateral-dependent impaired loans | Maximum |  |
Unobservable Inputs |  |
Impaired loans unobservable inputs (as a percent) | 1 | 0.90
Discount for lack of marketability and current conditions | Level 3 | Collateral based measurements | Collateral-dependent impaired loans | Weighted Average [Member] |  |
Unobservable Inputs |  |
Impaired loans unobservable inputs (as a percent) | 0.437 |
Constant prepayment rate (CPR) | Level 3 | Discounted cash flows | Mortgage servicing rights | Minimum |  |
Unobservable Inputs |  |
Mortgage servicing rights unobservable inputs (as a percent) | 0.162 | 0.102
Constant prepayment rate (CPR) | Level 3 | Discounted cash flows | Mortgage servicing rights | Maximum |  |
Unobservable Inputs |  |
Mortgage servicing rights unobservable inputs (as a percent) | 0.305 | 0.281
Constant prepayment rate (CPR) | Level 3 | Discounted cash flows | Mortgage servicing rights | Weighted Average [Member] |  |
Unobservable Inputs |  |
Mortgage servicing rights unobservable inputs (as a percent) | 0.228 |
Discount rate | Level 3 | Discounted cash flows | Mortgage servicing rights | Minimum |  |
Unobservable Inputs |  |
Mortgage servicing rights unobservable inputs (as a percent) | 0.083 | 0.093
Discount rate | Level 3 | Discounted cash flows | Mortgage servicing rights | Maximum |  |
Unobservable Inputs |  |
Mortgage servicing rights unobservable inputs (as a percent) | 0.111 | 0.121
Discount rate | Level 3 | Discounted cash flows | Mortgage servicing rights | Weighted Average [Member] |  |
Unobservable Inputs |  |
Mortgage servicing rights unobservable inputs (as a percent) | 0.085 |
Discount for lack of marketability | Level 3 | Appraisals trade publications and auction values | Repossessions | Minimum |  |
Unobservable Inputs |  |
Repossessions unobservable inputs (as a percent) | 0 | 0.03
Discount for lack of marketability | Level 3 | Appraisals trade publications and auction values | Repossessions | Maximum |  |
Unobservable Inputs |  |
Repossessions unobservable inputs (as a percent) | 0.16 | 0.25
Discount for lack of marketability | Level 3 | Appraisals trade publications and auction values | Repossessions | Weighted Average [Member] |  |
Unobservable Inputs |  |
Repossessions unobservable inputs (as a percent) | 0.08 |
Discount for lack of marketability | Level 3 | Appraisals | Other real estate | Minimum |  |
Unobservable Inputs |  |
Other real estate unobservable inputs (as a percent) | 0.06 | 0
Discount for lack of marketability | Level 3 | Appraisals | Other real estate | Maximum |  |
Unobservable Inputs |  |
Other real estate unobservable inputs (as a percent) | 0.13 | 0.11
Discount for lack of marketability | Level 3 | Appraisals | Other real estate | Weighted Average [Member] |  |
Unobservable Inputs |  |
Other real estate unobservable inputs (as a percent) | 0.07 |

X
- Definition Value of input used to measure impaired loans. + References No definition available. + Details
Name: | source_ImpairedLoansMeasurementInput
Namespace Prefix: | source_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Value of input used to measure repossessions owned by financial institution which is not directly related to its business. + References No definition available. + Details
Name: | source_RepossessionsMeasurementInput
Namespace Prefix: | source_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FairValueInputsQuantitativeInformationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of input used to measure real estate owned by financial institution by financial institution which is not directly related to its business. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_OtherRealEstateOwnedMeasurementInput
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Value of input used to measure servicing asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_ServicingAssetMeasurementInput
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=source_CollateralBasedMeasurementsValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=source_ImpairedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_ValuationTechniqueDiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=source_MortgageServicingRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=source_AppraisalsTradePublicationsAndAuctionValuesValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=source_RepossessionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=source_AppraisalsValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=source_OtherRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=source_MeasurementInputDiscountForLackofMarketabilityandCurrentConditionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputConstantPrepaymentRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |