v2.4.0.8

Organization (Details Textual) (USD $)	12 Months Ended
Organization (Details Textual) (USD $)	Mar. 31, 2013	Mar. 31, 2012
Limited Partners' Capital Account, Units Authorized	200,000
Limited Partner Units Price Per Unit	$ 1,000
Proceeds From Issuance Of Limited Partners Units	$ 36,497,000
Limited Partner Units	36,497	36,497
Percentage Of Gross Proceeds Designated As Reserves	5.00%
Local Limited Partnerships Reserves	$ 604,000	$ 37,000
Limited Partners Cumulative Earnings Sharing Percentage	99.00%
General Partner Cumulative Earnings Sharing Percentage	1.00%
Net Proceeds From Sale Refinancing Limited Partners Sharing Percentage	95.00%
Net Proceeds From Sale Refinancing General Partner Sharing Percentage	5.00%
First Series [Member]
Limited Partners' Capital Account, Units Issued	50,000
Alza Corporation [Member]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	90.00%
Boston Financial Bfg Investments Llc [Member]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	9.00%

Percentage of cumulative earnings allocated to the general partner based on the sharing of income or losses between general and limited partners as specified in the partnership agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	bftcviii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of cumulative earnings allocated to the limited partners based on the sharing of income or losses between general and limited partners as specified in the partnership agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	bftcviii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The average number of shares or units issued and outstanding that are used in calculating basic and diluted EPS.

+ References

No definition available.

+ Details

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Namespace Prefix:	bftcviii_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the per unit price of limited partner units.

+ References

No definition available.

+ Details

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Namespace Prefix:	bftcviii_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the amount designated as reserves, under the partnership agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	bftcviii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The percentage of cumulative amount of earnings allocated to limited partners as a result of net proceeds from sale or refinancing.

+ References

No definition available.

+ Details

Name:	bftcviii_NetProceedsFromSaleRefinancingGeneralPartnerSharingPercentage
Namespace Prefix:	bftcviii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of cumulative amount of earnings allocated to general partners as a result of net proceeds from sale or refinancing.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
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- Definition

Represents the percentage of gross proceeds designated as reserves.

+ References

No definition available.

+ Details

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Namespace Prefix:	bftcviii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from the issuance of limited partners units during the period.

+ References

No definition available.

+ Details

Name:	bftcviii_ProceedsFromIssuanceOfLimitedPartnersUnits
Namespace Prefix:	bftcviii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

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

- Definition

The number of limited partner units authorized to be issued.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-Subparagraph (SAB TOPIC 4.F)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 4

-Section F

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 87-21

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Practice Bulletin (PB)

-Number 14

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The number of limited partner units issued.

+ References

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
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BOSTON FINANCIAL TAX CREDIT FUND VIII LP 10-K