Name:	bke_OtherThanTemporaryImpairmentLossesInvestmentsHeldtoMaturitySecuritiesAtPointInTime
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Data Type:	xbrli:monetaryItemType
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This item represents other-than-temporary impairment for securities, at a point in time, which are categorized as trading securities.

No definition available.

Name:	bke_OtherThanTemporaryImpairmentLossesTradingSecuritiesSecuritiesAtPointInTime
Namespace Prefix:	bke_
Data Type:	xbrli:monetaryItemType
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This item represents the gross unrealized gains for securities, at a point in time, which are categorized as trading securities.

No definition available.

Name:	bke_TradingSecuritiesUnrealizedHoldingGainAtPointInTime
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Data Type:	xbrli:monetaryItemType
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This item represents the gross unrealized losses for securities, at a point in time, which are categorized as trading securities.

No definition available.

Name:	bke_TradingSecuritiesUnrecognizedLoss
Namespace Prefix:	bke_
Data Type:	xbrli:monetaryItemType
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- References

No definition available.

Name:	us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiAbstract
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Cost of investment in debt investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

No definition available.

Name:	us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCost
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

Name:	us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
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Data Type:	xbrli:monetaryItemType
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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

Name:	us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Namespace Prefix:	us-gaap_
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Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity).

No definition available.

Name:	us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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- References

No definition available.

Name:	us-gaap_HeldToMaturitySecuritiesClassifiedAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563

Name:	us-gaap_HeldToMaturitySecuritiesFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878