Schedule of Value of Business Acquired (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Balance at beginning of year	$ 8,955,249	$ 9,876,647
Value of business acquired	586,840
Imputed interest at 7% included in earnings	613,028	670,565
Amortization included in earnings	(1,728,157)	(1,457,390)
Shadow amortization included in other comprehensive income	(5,528)	(134,573)
Net amortization	(1,120,657)	(921,398)
Balance at end of year	$ 8,421,432	$ 8,955,249

Represents the monetary amount of Imputed interest on value of business acquired, during the indicated time period.

No definition available.

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Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the monetary amount of Shadow amortization included in other comprehensive income, during the indicated time period.

No definition available.

Name:	SNFCA_ShadowAmortizationIncludedInOtherComprehensiveIncome
Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Represents the monetary amount of Value of business acquired, balance at start of period, as of the indicated date.

No definition available.

Name:	SNFCA_ValueOfBusinessAcquired
Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the monetary amount of Value of business acquired - amortization, during the indicated time period.

No definition available.

Name:	SNFCA_ValueOfBusinessAcquiredAmortization
Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the monetary amount of Value of business acquired - net amortization charged to income, during the indicated time period.

No definition available.

Name:	SNFCA_ValueOfBusinessAcquiredNetAmortizationChargedToIncome
Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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Value of Business Acquired, Intangible Assets and Goodwill.

No definition available.

Name:	SNFCA_ValueOfBusinessAcquiredOnIntangibleAssetsAndGoodwill
Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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