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Description of Business - Additional Information (Detail)	3 Months Ended
	Apr. 04, 2021 ft² Store Segment
Description Of Business [Line Items]
Number of operating stores | Store	430
Area of traditional sporting goods store | ft²	11,000
Number of reportable segment | Segment	1
Big 5 Corp [Member]
Description Of Business [Line Items]
Subsidiary interest ownership percentage	100.00%
Big 5 Service Corp [Member] | Big 5 Corp [Member]
Description Of Business [Line Items]
Subsidiary interest ownership percentage	100.00%

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Description of business.

+ References

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- Definition

Area of a real estate property.

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

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Represents the number of stores.

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