Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent.

No definition available.

Name:	ssii_OtherComprehensiveIncomeDefinedBenefitPlanAdjustmentNetOfTaxPortionAttributableToParent
Namespace Prefix:	ssii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Income Tax - Schedule of Deferred Income Tax Benefit Recognized (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Deferred taxes benefit / (expense) recognized on:
Total	$ 6,456	$ 5,772	$ 5,253	$ 5,772
Federal [Member]
Deferred taxes benefit / (expense) recognized on:
Total
State [Member]
Deferred taxes benefit / (expense) recognized on:
Total
Retirement Benefits [Member]
Deferred taxes benefit / (expense) recognized on:
Total	$ 6,456	$ 5,772	$ 5,253	$ 5,772