14) Revenues From Contracts With Customers (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Text Block [Abstract]
Revenue recognized included in the opening contract liability	$ 880,633	$ 889,578	$ 1,831,406	$ 1,631,098

Represents the monetary amount of Revenue Recognized Included in the Opening Contract Liability, during the indicated time period.

No definition available.

Name:	snfc_RevenueRecognizedIncludedInTheOpeningContractLiability
Namespace Prefix:	snfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration