Name:	BNSO_StockholdersEquityDetailsNarrativeAbstract
Namespace Prefix:	BNSO_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Amount of decrease (increase) in additional paid in capital (APIC) for the increase in carrying amount of redeemable preferred stock.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 3.C)
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
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Data Type:	xbrli:monetaryItemType
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Amount of paid and unpaid cash, stock, and paid-in-kind (PIK) dividends declared, for example, but not limited to, common and preferred stock.

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-Publisher FASB
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-Topic 942
-SubTopic 405
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The cash outflow to reacquire common stock during the period.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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Balance Type:	credit
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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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-Name Accounting Standards Codification
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