SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Reclassifications Out of Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
Dec. 30, 2012
Defined Benefit Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Amortization of Gains (Losses)	$ 16,697
Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Amortization of Gains (Losses), Net of Tax	$ (2,485)

The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation after tax.

No definition available.

Name:	sr_DefinedBenefitPlanAmortizationofPriorServiceCostCreditNetofTax
Namespace Prefix:	sr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration