Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

+ Details

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Period Type:	instant

- Definition

Represents the number of dry bulk vessel leases.

+ References

No definition available.

+ Details

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Namespace Prefix:	seb_
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Balance Type:	na
Period Type:	instant

- Definition

Represents the term of the derivative contract entered into by the entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	seb_
Data Type:	xbrli:durationItemType
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- Details

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Balance Type:	na
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- Definition

Nominal mass used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

- Definition

Nominal volume used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959

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- Details

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Derivatives and Fair Value of Financial Instruments (Details 2) (USD $)	3 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended
	Apr. 04, 2015 bu	Dec. 31, 2014 bu	Apr. 04, 2015 lb	Dec. 31, 2010 agreement
Net commodity purchase contracts \| Grain
Derivative commodity instruments
Nonmonetary notional amount	33,775,000	10,697,000
Net commodity purchase contracts \| Hogs
Derivative commodity instruments
Nonmonetary notional amount	24,200,000	19,800,000
Net commodity purchase contracts \| Sugar
Derivative commodity instruments
Nonmonetary notional amount	9,390,000	15,551,000
Net commodity purchase contracts \| Soybean oil
Derivative commodity instruments
Nonmonetary notional amount	960,000	19,620,000
Net commodity purchase contracts \| Soybean meal
Derivative commodity instruments
Nonmonetary notional amount	365,000	85,000
Net commodity purchase contracts \| Dry whey powder
Derivative commodity instruments
Nonmonetary notional amount		88,000	264,000
Net commodity purchase contracts \| Cheese
Derivative commodity instruments
Nonmonetary notional amount	40,000
Net commodity sale contracts \| Heating oil
Derivative commodity instruments
Nonmonetary notional amount		4,326,000
Foreign currencies
Derivative commodity instruments
Notional amounts	92,901,000	143,961,000	92,901,000
Interest rate swaps
Derivative commodity instruments
Notional amounts	163,000,000	163,000,000	163,000,000	25,000,000
Number of derivative agreements	7	7	7	3
Term of derivative contract				10 years
Eight-year interest rate exchange agreements
Derivative commodity instruments
Notional amounts	22,000,000		22,000,000
Number of derivative agreements		4
Number of dry bulk vessel leases	4		4
Term of derivative contract		8 years