Area of a real estate property.

No definition available.

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Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Details

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Period Type:	instant

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Term of the lessee's leasing arrangement renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LesseeLeasingArrangementsOperatingLeasesRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from other borrowing not otherwise defined in the taxonomy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Income earned by providing the use of assets to an outside party in exchange for a payment or series of payments that is nonoperating in nature.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=djco_NewDawnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=djco_MarginAccountMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=djco_CoronaCAOfficeMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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- Details

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Note 4 - Debt and Commitments (Details Textual) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended	0 Months Ended
Note 4 - Debt and Commitments (Details Textual) (USD $)	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012 acre	Sep. 13, 2013	Sep. 13, 2013	Dec. 04, 2012
Commitments and Contingencies Disclosure [Abstract]
Proceeds from Other Debt		$ 29,493,000us-gaap_ProceedsFromOtherDebt
Operating Leases, Rent Expense	1,182,000us-gaap_LeaseAndRentalExpense	884,000us-gaap_LeaseAndRentalExpense	455,000us-gaap_LeaseAndRentalExpense
Corona, CA Office [Member] \| Monthly Rent [Member]
Commitments and Contingencies Disclosure [Abstract]
Operating Leases, Rent Expense				12,000
Area of Real Estate Property				7,100
Logan, Utah Office [Member] \| Monthly Rent [Member]
Commitments and Contingencies Disclosure [Abstract]
Operating Leases, Rent Expense				42,000
Area of Real Estate Property				30,200
Rental Income, Nonoperating				5,000
San Francisco Office [Member]
Commitments and Contingencies Disclosure [Abstract]
Lessee Leasing Arrangements, Operating Leases, Renewal Term	5 years
Area of Real Estate Property	6,200
San Francisco Office [Member] \| Monthly Rent [Member]
Commitments and Contingencies Disclosure [Abstract]
Operating Leases, Rent Expense	22,000
Margin Account [Member]
Commitments and Contingencies Disclosure [Abstract]
Debt Instrument, Interest Rate, Effective Percentage	0.75%
Margin Account [Member] \| Fed Funds Rate [Member]
Commitments and Contingencies Disclosure [Abstract]
Debt Instrument, Basis Spread on Variable Rate					50.00%
ISD Corporation [Member]
Commitments and Contingencies Disclosure [Abstract]
Proceeds from Other Debt						15,500,000
New Dawn [Member]
Commitments and Contingencies Disclosure [Abstract]
Proceeds from Other Debt							$ 14,000,000