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Description of Business - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017 ft² Store Segment
Description Of Business [Line Items]
Number of operating stores | Store	435
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]
Description Of Business [Line Items]
Subsidiary interest ownership percentage	100.00%

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- Definition

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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- Definition

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.

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- Definition

Represents the number of stores.

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