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

Represents the monetary amount of Increase Dececrease in Unrealized gains on restricted assets, during the indicated time period.

No definition available.

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

Represents the monetary amount of Increase (Decrease) in Other comprehensive income (loss), Balance, during the indicated time period.

No definition available.

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

Represents the monetary amount of Increase (Decrease) in Unrealized gains on fixed maturity securities available-for-sale, during the indicated time period.

No definition available.

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

Represents the monetary amount of Unrealized gains on cemetery perpetual care trust investments, as of the indicated date.

No definition available.

Name:	SNFCA_UnrealizedGainsOnCemeteryPerpetualCareTrustInvestments1
Namespace Prefix:	SNFCA_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the monetary amount of Unrealized gains on restricted assets, as of the indicated date.

No definition available.

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

Represents the monetary amount of Unrealized gains on fix maturity securities available-for-sale, as of the indicated date.

No definition available.

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

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e637-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e681-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 5A
-URI https://asc.fasb.org/extlink&oid=123594809&loc=SL116692626-108610

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669646-108580

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580

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

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30)(a)(4))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(a)(3))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e681-108580

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

- References

No definition available.

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

Adjustments to temporary equity resulting from foreign currency translation adjustments.

No definition available.