XML 25 R30.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Marketable Securities (Schedule of investments measured at fair value) (Details) (USD $) | Apr. 30, 2015 | Jul. 31, 2014
--- | --- | ---
First Eagle Global CL I [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | $ 280,717us-gaap_InvestmentsFairValueDisclosure / us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis = mays_InvestmentOneMember | $ 273,000us-gaap_InvestmentsFairValueDisclosure / us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis = mays_InvestmentOneMember
Parnasus Core Equity Investor CL [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 297,992us-gaap_InvestmentsFairValueDisclosure / us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis = mays_InvestmentTwoMember | 277,571us-gaap_InvestmentsFairValueDisclosure / us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis = mays_InvestmentTwoMember
Columbia Flexible Income CL A [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value | 278,822us-gaap_InvestmentsFairValueDisclosure / us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis = mays_InvestmentThreeMember |
Transamerica Tactical Income CL A [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value |  | $ 269,649us-gaap_InvestmentsFairValueDisclosure / us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis = mays_InvestmentFourMember

X
- Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph a, f, g -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis=mays_InvestmentFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis=mays_InvestmentOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis=mays_InvestmentThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis=mays_InvestmentTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |