XML 86 R74.htm IDEA: XBRL DOCUMENT
v3.20.2

12) Mortgage Servicing Rights: Assumptions used in determining MSR value (Details) - Decimal | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2020 | Dec. 31, 2019
Text Block [Abstract] |  |
Prepayment Speeds | 16.7 | 15.3
Average Life in Years of MSR | 5 years 22 days | 5 years 3 months 8 days
Discount Rate | 9.5 | 9.51

X
- References No definition available. + Details
Name: | snfc_AverageLifeInYears
Namespace Prefix: | snfc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the Discount Rate, during the indicated time period. + References No definition available. + Details
Name: | snfc_DiscountRate
Namespace Prefix: | snfc_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | snfc_PrepaymentSpeeds
Namespace Prefix: | snfc_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

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