Income Taxes (Details) (USD $)	Mar. 30, 2013
Income Taxes
One-time tax benefit on enactment of law	$ 7,945,000
One-time Federal blender's credits that will be recognized as revenues	$ 11,260,000

Represents the one-time Federal blender's credits that will be recognized as revenues.

No definition available.

Name:	seb_IncomeTaxesFederalBlendersOneTimeTaxCreditToBeRecognizedAsRevenues
Namespace Prefix:	seb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant